Technical Terms and Definitions Related To Headphones – Glossary

0-9

• 2.4 GHz — A newly allocated wireless frequency. In general 2.4 GHz wireless headsets are less susceptible to interference.

A

• Analog — Generally, a mechanism that represents data using a continuously changing variable. Usually, a voltage that continuously tracks and represents sound pressure level.
• Articulate — Able to reproduce many instruments clearly.
• Accurate — Presenting the music in a way that is close to how it sounded when it was originally recorded.
• Amplifier — A device that increases the amplitude of an electric signal. Headphone amps allow the use of headphones that require more voltage or current than an mp3 player, phone, laptop, etc can provide.
• Aggressive —  Forward and bright sonic character.
• Airy — Spacious. Open. Instruments sound like they are surrounded by a large reflective space full of air. Good reproduction of high frequency reflections. High frequency response extends to 15 or 20 kHz.
• Ambience —  Impression of an acoustic space, such as the performing hall in which a recording was made.
• Analytical —  Highly detailed.
• Attack — The leading edge of a note and the ability of a system to reproduce the attack transients in music.
• Attack (2) — The time taken for a musical note to reach its peak amplitude eg. notes will tend to sound more defined rather than blended with other notes.
• Accessory Pack for Executive Pro Systems — The office headset Accessory Pack includes an amplifier adapter (removing the need for batteries) and a 7ft. Extension Cord for maximum reach while on the phone. Accessory packs can be purchased separately from our accessories page.
• ACD — Automatic Call Distribution — A type of phone system used in professional call centers where incoming calls are routed to the different operators automatically.
• Acoustic Coupler — A special seal on some headsets (notably the Plantronics M130) that allows better caller focus by blocking out unwanted sounds.
• Automated Handset Lifter — Used with the Plantronics Wireless Headset System, this device allows you to answer the phone without returning to your desk to lift the receiver. The remote answering platform for the Plantronics Wireless Headset System can be purchased in our Wireless section.
• Airline adapter — An adapter that connects the mini plug or full-sized jack of most headphones to the two 1/8″ mini plugs that most airplanes use for audio.
• Armature — A type of headphone driver, armatures consist of a moving magnet connected to a diaphragm that creates sound when an electrical current is applied. Armatures are mostly used for in-the-ear earbuds and hearing aids because of their small size and low impedance. However, they’re generally limited when it comes to reproducing frequencies lower than 20 Hz and higher than 16,000 Hz, and require a good seal in your ear to deliver their full audio range.
• Around-the-ear — This kind of earcup is large and fits over the ear, usually surrounding it with an extra roll of material. Also known as a sealed design, it helps keep outside noise from penetrating the ear. It also prevents the audio being played through the headphones from disturbing others. However, since sound has a tendency to reverberate in enclosed spaces, this type of design may cause some minor unwanted resonance.
• Asymmetrical cord — Extends from both earcups, with one cable longer than the other. Both cords come together off center, to the side of the neck, or close to one ear. This design keeps the cord to the side and out of the way.
• A2DP — Abbreviation for “Advanced Audio Distribution Profile”. A2DP is a Bluetooth profile that transmits stereo sounds. Also referred to as the AV profile, it is designed to transfer a stereo audio stream (such as music) from an mp3 player to a headset or car radio. Plantronics products such as Voyager Legend and the BackBeat family support the A2DP profile.
• Ac Adapter — The unit that provides electrical power to the system and charges stationary batteries; usually plugs into a wall outlet.
• Active Noise Cancellation — Also known as active noise control (ANC) or active noise reduction (ANR), it is a method for reducing unwanted sound by the addition of a second sound (“anti-noise”) specifically designed to cancel the first.
• Adapter — A device used for connecting two or more apparatus.
• Audio Sensing — A special feature supported by Plantronics wireless devices that can detect audio signal at the USB port and automatically establish a PC radio link between the base and wireless headset without the user having to press the PC call control button
• Audioiq® — AudioIQ makes wireless conversations effortless and pleasant, regardless of the environment. For incoming calls, AudioIQ automatically adapts to background noise levels and intelligently improves the receive quality, clarity and volume level. For outgoing calls, AudioIQ reduces background noise for listeners up to 7-8 decibels, or by approximately 50 percent. It also minimizes interference from artifacts such as speech distortions to maintain exceptionally clear voice intelligibility.
• Auto Answer — A switch which allows calls to be automatically answered by putting on the headset.
• AVRCP (Audio/video Remote Control Profile) — A type of Bluetooth profile included in some Plantronics headsets. AVRCP (Audio/Video Remote Control Profile): Enables you to play, pause, and stop music, as well as track forward and backward.

B

• Balanced (equipment) — Using a pair of impedance balanced lines to reduce interference, especially with long cables.
• Balanced (sound/music presentation) — No frequencies are emphasized over the rest.
• Bass — Lower frequencies.
• Breath — Good sounds from breaths of people playing wind instruments/singing/etc, comes from good upper mids and highs.
• Bright — Emphasis overall on the treble.
• Brilliance — Clarity. Mainly controlled by the reproduction of the frequencies between 6kHz to 16kHz.
• Behind-the-neck —Behind-the-neck headphones are also called ‘neckband’ headphones. They have a headband that fits behind the neck rather than over the head. They are most commonly used in exercise or active-use applications since they’re quite stable during movement. Fashionistas like them when they don’t want to mess up their hair, or when wearing a hat or helmet.
• Bassy —  Emphasized Bass.
• Blanketed — Weak highs, as if a blanket were put over the speakers.
• Bloated —  Excessive mid bass around 250 Hz. Poorly damped low frequencies, low frequency resonances. See tubby.
• Blurred — Poor transient response. Vague stereo imaging not focused.
• Body — Fullness of sound, with particular emphasis on upper bass; opposite of Thin.
• Boomy — Excessive bass around 125 Hz. Poorly damped low frequencies or low frequency resonances.
• Boxy — Having resonances as if the music were enclosed in a box. Sometimes an emphasis around 250 to 500 Hz.
• Biaural and Binaural — (Compare with Monaural)A style of headset with speakers for both ears. Typically these offer the user a greater degree of caller focus.
• Bluetooth — A new protocol developed jointly by industry leaders in many fields, including Microsoft, Plantronics, Nokia, Ericsson, IBM, 3Com and Motorola. Bluetooth is still in its infancy, but the design allows for seamless, wireless, automatic connectivity between a large number of devices. Bluetooth headsets are among the first Bluetooth devices available.
• Bluetooth version 2.0 — Bluetooth 2.0 is backward-compatible with 1.1. The main improvement is the introduction of an Enhanced Data Rate for both data and voice packets. This additional speed is obtained by using a different radio transmission. Other advantages are three times faster transmission speed, lower power consumption, and simplification of multi-link capabilities.
• Boom Microphone — A boom microphone is a microphone that is held in a fixed position from your mouth by an arm (or boom). It has significant benefits over a fixed, desktop microphone (such as the one in your telephone when it is used in ‘speakerphone mode’) because as you move your head around, the volume that the caller hears remains constant.
• BroadBass speakers — (GN Netcom headsets)Speakers with a wide dynamic range, particularly good at reproducing the lower or bass tones. This term is used to describe some headsets by GN Netcom, that have been specifically designed to minimize the ‘tinny’ sound that cheaper headsets can be plagued with.
• Busy Light — The Busy Light is an easily visible light which indicates to others when you are on the line. Great for preventing interruptions and monitoring group phone activity. Works with or without a headset. Busy Lights can be purchased separately from our accessories page.
• Binaural recording — A way of recording audio that produces a 360-degree listening experience when heard through headphones. Any pair of headphones with good right and left channel isolation can sufficiently reproduce this effect, although higher-quality headphones will do a better job.

C

• Chesty — The vocalist sounds like their chest is too big. Comes from emphasis of low frequencies between 125Hz and 250Hz.
• Circumaural — Headphone where a pad sits around the ear.
• Clear — Shows the music as it is.
• Clipping — Certain frequencies are severely cut off due to the inability of the source or amp to supply enough current.
• Closed — The back of the headphone is closed. Closed headphones generally leak less than open ones.
• Coaxial — Many HeadRoom digital to analog converter (DAC) products have a “coaxial digital” input. This is a 75 Ohm S/PDIF digital audio input. The word “coaxial” specifically refers to 75 Ohm cables which typically use a coaxial construction, which refers to a center conductor and an outside conductor which completely surrounds the center conductor. Both conductors share the same center axis and are therefor called “co-axial.”
• Coherent — A descriptive audio term when all spectral components of the audio are passing through the system at exactly the same time. When audio is coherent, imaging is precise and stable with instruments clearly defined and natural sounding. When incoherent, may become edgy and hard sounding, lacking image depth.
• Crossfeed — An electronic circuit that serves to make the audio image on headphones more like that heard on speakers. It takes the signal from each channel, delays it for a few hundred microseconds, and crossfeeds it over to the opposite channel to mimic the acoustics of the left speaker sound reaching the right ear and vice versa. It both improves the audio image on headphones and reduces listening fatigue.
• Congested — Smeared, confused, muddy, and flat; lacking transparency.
• Coloured — Having timbres that are not true to life. Non flat response; peaks or dips.
• Cool — Moderately deficient in body and warmth, due to progressive attenuation of frequencies below about 150Hz.
• Crisp — Extended high frequency response, especially with cymbals.
• Call Clarity™ — (Plantronics Systems)Plantronics Call Clarity™ system uses electronic signal processing to enhance transmission and reception through innovative noise reduction techniques that result in the clearest possible calls. With Call Clarity™, the headset wearer benefits from less phone line disturbance and background room noise. For both the wearer and the listener, the Call Clarity™ system ensures less confusion as to who is speaking.
• Circumaural — (Compare with Intraural, Supraural)A style of speaker that covers the entire ear, blocking out all sounds. This is typically not found on headsets (apart from specialist models) but is more common on headphones.
• Connector Cord — The cord that connects your base unit amplifier and your telephone.
• Convertible — (Contrast with Reversible)A headset style that can be quickly reconfigured to be worn either as an over-the-head headset or alternatively as an on-the-ear model. (Please note the Plantronics DuoPro model can also be configured as a behind-the-neck headset).
• Call Button — The button on the headset used to answer or terminate calls.
• Clearline™ — A Plantronics audio technology that helps to reduce common problems with business conversations that stem from poor audio quality, including repeats, errors, and listening fatigue. It is compatible with both traditional phones and headsets as well as wideband VoIP phones and headsets. It provides advanced echo management, delivers consistent and comfortable call volume, reduces background noise, and protects against loud noises.
• Configuration Dial — Configures volume, desk phone, peripherals, etc.
• Control Panel — Control Panel is part of the Windows operating system. Going into the “Sound and Audio Devices” section of the Control Panel allows you to change the settings for your computer’s sound devices
• Cordless Amplifier — These units connect into the phone’s hand receiver port and come with a remote that can be used away from the desk; they make the sound louder. Abbreviated as CA.
• Cordless System — A set of products that comes with both a cordless amplifier and a headset. Abbreviated as CS.
• Cross Talk — Unwanted signals in a communication channel (as in a telephone, radio, or computer) caused by transference of energy from another circuit (as by leakage or coupling).

D

• DAC (Digital-to-Analog Converter) — Converts digital audio into an analog signal that can drive a headphone
• Dark — Lack of emphasis in the highs and upper mids
• Decay — How long or short sound lingers after it is produced. Quick decay means silence will be silence, slow decay means that the sound from before will stay during the silence.
• Definition — Ability to reveal subtle details in sound.
• Delicate — High frequencies extending out without dips and peaks past 15kHz.
• Depth (soundstage) — Sense of how near or far away instruments are.
• Damping Factor — Typically the input impedance of a speaker/output impedance of the amplifier. An 8 Ohm speaker driven by a power amplifier with an output impedance of 0.8 Ohms would have a damping factor of 10. Typically, damping factors of 10 or more are considered good.
• dBr — “Amplitude (dBr)” is listed on the Y axis of our frequency response measurement data. “dBr” stands for Decibels- relative. The graph is showing the amplitude of each frequency’s response relative to the amplitude of the other frequencies, not the actual number of decibels measured at each frequency.
• Digital — Generally a system using binary data (ones and zeros) to represent information. In audio, a digital signal is a series of binary numbers that represent the sound pressure level sampled in a series over time.A Digital to Analog converter (DAC) is required to convert the digital signal into the analog signal that can actually move your headphone drivers to make sound.
• Digital Inputs — Any input to a digital to analog converter (DAC); for example USB, or S/PDIF Toslink optical or coax digital inputs.
• Distortion — Any new feature in a signal due to some imperfection in the device through which it passes. For example, putting in a 1000 Hertz tone, and getting a small amount of 2000 Hertz tone out along with the original 1kHz tone.
• Driver — The element inside the headphone that converts an electrical signal into sound pressure that is heard by the ear. Most headphones use a dynamic driver which is a coil of wire suspended in a magnet and attached to a diaphragm, much like a very small speaker cone. Other popular headphones use planar magnetic or electrostatic driver types.
• Definition (or resolution) — The ability of a component to reveal the subtle information that is fundamental to high fidelity sound.
• Depth — A sense of distance (near to far) of different instruments.
• Detail — The most delicate elements of the original sound and those which are the first to disappear with lesser equipment.
• Detailed — Easy to hear tiny details in the music; articulate. Adequate high frequency response, sharp transient response.
• Dry — Lack of reverberation or delay as produced by a damped environment. May comes across as fine grained and lean. Opposite of Wet.
• Dynamic — The suggestion of energy and wide dynamic. Related to perceived speed as well as contrasts in volume both large and small.
• DECT — (1.9 GHz Wireless Frequency)1.9GHz DECT is a digital wireless technology which originated in Europe, but is now being adopted increasingly worldwide, for cordless telephones, wireless offices and even wireless telephone lines to the home.  DECT has been designed and specified to be more compatible with other wireless technologies which can increase call clarity and security on headsets that use this standard.
• Directional — (Contrast with Omni-Directional)Usually applied to a microphone, when it is capable of receiving sounds from only one direction.
• DC Adapter — The optional amplifier adapter provides power for your amplifier and eliminates the need for batteries. Just plug it in, and forget it! Amplifier adapters can be purchased separately from our accessories page.
• Device Manager — A Windows or Android program. It allows users to view and control the hardware attached to the computer. One feature of Device Manager is its ability to list the drivers installed on your computer system.
• Docking Station — A term for headset base, i.e., where the headset is docked for charging. See base.
• Drop-out — A momentary loss of audio signal.
• DSP — Abbreviation for “digital signal processing”. Mathematical manipulation of an information signal to actively reduce background noise for improved sound quality. This can include equalization (bass and treble adjustment), AEC, noise reduction and audio leveling. For Plantronics products, DSP refers to computer headsets that connect via the USB port rather than the computer’s sound card.
• Dynamic Noise Reduction — Used on many Plantronics products where noise in the environment is detected and noise reduction algorithms are adjusted automatically to address the noise.

E

• Electrostatic/Electrostats —Headphones that use electrostatic drivers. Most electrostats are made by Stax, but other companies have also made electrostatic headphones. All electrostats require an electrostatic amplifier to function.
• Energy/Energetic (sound attribute)
• Extension — How high or low a headphone acceptably reproduces sound
• Euphonic — Appealing coloration and distortion.
• Ear Headphone — Ear headphones are always called in-ear headphones by us, but can be referenced by numerous terms including: in-ear monitor, IEM, ear canal headphones, earphones, and canal-phones. In-ear headphones are inserted into and seal the ear canal, and provide the highest amount of isolation from outside noise of any headphone type including noise-canceling headphones. There are two types of in-ear headphones: deep sealing and shallow sealing. With deep seating in-ear headphones the tip of the earphone goes in about half the length of the ear canal and seats in the bony section of the ear canal; this type provides about -23dB of isolation. Shallow seating types seal closer to the entrance to the ear canal and provide about -15dB of isolation.
• Earbud — Earbud headphones are the ones that come with iPods or smartphones. Earbuds have small earpieces that are positioned in the small cupped area (concha) around the outer entrance to the ear canal in your outer ear (pinna). They most commonly simply rest in the concha, but some have attachments or ear clip features to improve wearing stability. Earbuds are all typically fairly similar in size, but they should not be mistaken for in-ear headphones, which seal in the ear canal like a true earplug and can typically sound much better than earbuds.
• Earpad — Otherwise known as supra-aural or on-ear headphones, earpad headphones have ear-pieces are sometimes literally flat pads against the ear, but can also be shallow bowl shaped, or deeper ear cups that are too small to fully surround the ear.
• Earphone — HeadRoom always calls this type of headphone ‘in-ear headphones,” but they are also known by numerous terms including: in-ear monitor, IEMs or ear canal headphones. In-ear headphones are inserted into and seal the ear canal just like an earplug, and thus provide the highest amount of isolation from outside noise of any headphone type including noise-canceling headphones. There are two types of in-ear headphones: deep sealing and shallow sealing. With deep seating in-ear headphones the tip of the earphone goes in about half the length of the ear canal and seats in the bony section of the ear canal; this type provides about -23dB or more of isolation. Shallow seating types seal closer to the entrance to the ear canal and provide about -15dB of isolation.
• Efficiency — Headphone efficiency is the measure of the relation ship between input signal level and how loud the headphones play. This can be a rather confusing measure and can be expressed in numerous ways: dB/Watt; dB/mW; dB/Volt. Some in-ear headphones have very high efficiency (~120dB/mW); difficult to drive full size headphone may be in the 90dB/mW; headphones to be driven by portable players should have about 95dB/mW or better efficient, and a 100 Ohm or lower impedance.
• Edgy — Too much high frequency response. Trebly. Harmonics are too strong relative to the fundamentals. Distorted, having unwanted harmonics that add an edge or raspiness.
• Ear clips — Often made of wire or plastic, ear clips fit around the back of the ear and hold the earbuds in place. Some ear clips are flexible, so that they can be manually formed to the ear for a more secure fit.
• Earbud gels — Also known as earbud “sleeves.” The rubber, foam, or silicone material on the end of most earbuds that fits into the ear canal. Many earbuds come with a variety of gel sizes to fit the unique size and shape of an individual’s ear canal. It’s important to use gels that fit properly. Gels too small may not create a tight enough fit with the ear canal, allowing the earbuds to fall out. Gels that are too large may cause pressure on the ear canal that can be uncomfortable and often painful over time.
• Earcup — The general term for the enclosure that rests against the ear and contains the drivers that reproduce sound. Earcups are traditionally connected by a headband that rests on top of the head. Earcups can either be sealed or open. A sealed design (also known as a closed design) completely covers and sits around the ears with extra padding to help block out external noise. Open earcups rest on top of the ear and allow some external noise to reach the ear.
• Ear hangers — Like ear clips, ear hangers are usually full, open loops that rest or hang around the ear to hold the earbuds in place. Sometimes also called “ear loops.”
• Eartip — A foam or plastic tip that attaches to a headset and fits snugly inside of your ear.

F

• Fast — Good reproduction of rapid transients which increase the sense of realism and “snap”.
• Fat — Sound with a lot of body.
• Fidelity — The ability to accurately reproduce sound.
• FLAC — A lossless audio format. FLAC files can be decompressed to what you get from the CD.
• Flat — No frequencies are emphasized over others.
• Forward(ness) — Aggressive. Makes listener feel closer to the instruments.
• Frequency — A property of waves. The count of how many cycles happen per second. Treble is high frequency sound and bass is low frequency.
• Filter Switch — This switch engages a filter that makes the sound slightly brighter (more highs). It is there to compensate for the crossfeed which causes in increase in low frequencies. The amount of increase in low frequencies is dependent on how much information is common to the left and right channel; the more common information the more the bass will boost through the crossfeed. Over time, our electronics circuits have gotten faster, and we’ve found less bass emphasis occurs when the crossfeed is switched on, and we have found the need to use this switch is substantially less.
• Full size — Also called “circumaural” or “over-ear” full-size cans have large earcups that completely cover the earlobes on most wearers.
• Focus — A strong, precise sense of image projection.
• Firefly™ — (Plantronics Systems)Firefly is a feature on some Plantronics headsets, integrating an on-line indicator at the tip of the microphone boom that flashes when in use, letting other people know that you are on a call.
• Flex-Grip™ — (Plantronics Wireless)Flex-Grip is a design style used to help an Over-the-Ear headset fit more comfortably and securely.
• FlexFit™ —(Plantronics Wireless)FlexFit is a design style for an intraural headset that improves the stability of the microphone.
• Folding headband — Many portable headphones use a headband that folds in on itself so that it can be easily stored for transport.
• Full Duplex Speakerphone — This term pertains to speaker phones that have minimal reduction of gain on the microphone when the far end is talking. This enables better two-way communication.

G

• Gentle — Opposite of edgy. The harmonics (of the highs and upper mids) are not exaggerated, or may even be weak.
• Grainy — A slightly raw, exposed sound which lacks finesse. Not liquid or fluid.
• Grip — A sense of control and sturdiness in the bass.
• Grungy — Lots of harmonic or I.M. (Intermodulation) distortion.
• Gain Switch — A coarse volume control for headphones of differing impedance. Roughly, set to low for 10 to 50 ohm; medium for 50 to 200 ohm, and high for 200 ohm and up. Headphones vary widely in their impedance and efficiency. In order to have the amplifier volume control operate somewhere between the 12 o’clock to 3 o’clock to achieve a normal listening level with the wide variety of headphones commonly encountered, a gain switch is used to adjust the gain range over which the amplifier operates.
• GN Netco — A subsidiary of GN Danavox, a Danish company. GN Netcom has over the last few years acquired many of the smaller brands of headset manufacturers, including Unex, ACS, Jabra and others.

H

• Harsh — Abrasive sounding due to an excess of upper mid range.
• Headstage — The perception of sound stage.
• High Midrange — Higher end of mid range, around 2kHz to 6kHz.
• Highs — The higher frequency notes, high pitched sounds – generally above roughly 6kHz.
• Hollow — Recessed mid range, causing the bass and high end to resound out over the mid range.
• Harmonic Distortion — Distortion artifacts that are exact integer distances higher in frequency than the originating tone, usually a result of non-linearities in the transfer function of an analog electronic device. For example: 1kHz might yield a little distortion at 2kHz, 3kHz, 4kHz, 5kHz, etc. Typically, it is thought the even harmonics (2, 4, 6, 8) sound better than odd harmonics (3, 5, 7, 9). This is somewhat true, but a gross oversimplification of the subject.
• Headphone Amplifier — A headphone amplifier is a miniature audio power amplifier specifically designed to drive the miniature audio drivers in headphones. Headphone amplifiers work essentially the same as power amplifiers used to drive speakers except they are much lower power and need to be capable of driving a wider range of impedance (~20-600 Ohms) than speaker amplifiers (4-8 Ohms). Headphone amplifiers typically range between 0.1 to 1 Watt and about 0.2 to 2 Ohms output impedance.
• Headphone Efficiency — A measure of how much energy it takes to drive headphones to a given listening level. Can be stated in numerous ways but generally in the form of dB/volt or dB/Watt.
• Headphone Sensitivity — see Headphone Efficiency.
• Honky — Like cupping your hands around your mouth. A bump in the response around 500 to 700 Hz.
• Hard — Too much upper midrange, usually around 3 kHz. Or, good transient response, as if the sound is hitting you hard. Uncomfortable, forward, aggressive sound with a metallic tinge.
• Headset — A number of headsets require an amplifier to function. Please be sure to verify what components the headset you’re looking at requires.
• Hand Receiver (Port) — The portion of the telephone that you hold in your hand when talking. It is generally attached to the phone with a coil cord. The hand receiver plugs into the phone’s hand receiver port (usually a square, modular plug).
• Handset — The part of a telephone system you pick up and put to your ear and speak into.
• Headset Port — Some, but not all, phones have a headset port. This headset port may be a round, 2.5 mm plug, or a square modular RJ9 plug. However, most Plantronics amplifiers are designed to plug into the telephone’s hand receiver port rather than the headset port.
• HFP — Abbreviation for “hands-free profile”. A more advanced version of the HSP Bluetooth profile. It allows voice dialing activation, redial, call transfer, and call answer/end capabilities.
• HSP — Abbreviation for “headset profile”. A Bluetooth® profile used for voice, mono music, and internet chat programs. This is the most commonly used profile, providing support for the popular Bluetooth® headsets to be used with mobile phones.

I

• I.E.M. — In-ear monitor – headphone that inserts into the ear canal. Usually designed to form a seal between the ear and the headphone, blocking outside sound
• Imaging — The sense of direction of an instrument or sound in ‘headspace’
• Impedance — The resistance. Requires more current to produce sound.
• In-Ear Monitor — Another term for In-ear headphones but also commonly known as IEMs, ear canal headphones, earphones, and canal-phones. In-ear headphones are inserted into and seal the ear canal and provide the highest amount of isolation from outside noise of any headphone type including noise-canceling headphones.
• Image Depth — The ability of an audio system to portray sounds in front of, and behind each other. Essentially, front to back imaging. Audio systems typically trade off a punchy sound for a deeply layered sound; a very few do both well.
• Image Width — The left to right width of the audio image. Typically within the boundary of the left and right speaker in a two-channel audio system, but may be all around in a multi-channel (surround-sound) system.
• Input Impedance — The effective resistance of the input to a device. Essentially, how hard a load it is to drive. Most good electronics have an input impedance in the many thousands of ohms and are easy to drive.
• Isolation — The ability of a pair of headphones to block outside/ambient sounds so that the listener can hear the music on the headphones more clearly. Can be measured as a broad band reduction in amplitude in a single number in dB; or shown as a graph indicating the amount of attenuation over the audio spectrum.
• Inline Volume Control — This type of volume control is built into the headset cord so you can change the volume of your headset in a natural and efficient manner.
• Intraural — (Compare with Supraural, Circumaural)A type of speaker that sits gently in the ear canal.
• Infrared (IR) transmission — Wireless headphones that use infrared transmission come with a transmitter that connects to an audio source’s headphone jack, stereo RCA output, or optical digital output. IR transmission works by sending out signals of infrared light from the transmitter to the headphones. The headphones must be within line of site of the transmitter, since the signal can’t pass through walls, furniture, and other obstacles. That’s part of why IR transmission usually has a shorter range than RF transmission.

J

• Juicy – Sound that has joie de vivre, energy and life.

K

• Key – A specific scale or series of notes defining a particular tonality. Keys may be defined as major or minor, and are named after their tonic or keynote. Thus the series of notes with intervals defining a major tonality and based on the key of C is the key of C major.

L

• Laid-back — Recessed, distant-sounding, having exaggerated depth, usually because of a dished midrange. Compare “Forward”.
• Liquid — Textureless sound.
• Low Level Detail — The quietest sounds in a recording.
• Low Midrange (Low Mids) — The audio frequencies between about 250Hz and 2000Hz.
• Lush — Very Rich/Full.
• Linear Amplifier — A broad category of electronic amplifiers with very linear gain curves. Usually, solid state, class A/B push/pull amplifiers. Generally as opposed to single output device, class-A amplifiers that have more non-linear gain curves.
• Listening Fatigue — The result of your brain having to struggle to properly place (localize) sounds in an artificial listening environment like speakers and headphones. Generally much worse on headphones, and can be minimized with use of the HeadRoom crossfeed circuit.
• Lush — A descriptive audio term usually attributed to vacuum tube audio gear which produces a large amount of even-order harmonic distortion. This type of distortion is often pleasant to the ear and produces a rich, warm sound.
• Lush (2) — A “lush” sound has a sense of warmth and fullness. Notes are more authoritative and have a sense of life about them. It is a sound free of any sibilance or brightness. It does not mean colored, however. It is an open and inviting sound enveloping the listener into its soundstage. (source: unkown headfier).
• Lift Lever — The Handset Lifter is a simple device that lifts your telephone receiver from its cradle and holds the line open while you talk. Perfect for reducing desktop clutter.
• Link Dropping — Link dropping means that the signal between the headset and the telephone periodically disconnects. If you experience link dropping, we recommend that you establish a new signal between the headset and the telephone by re-pairing or resubscribing your headset.

M

• Midrange (Mids) — Combination of Low Midrange and High Midrange, frequencies between 250Hz and 6kHz.
• Mellow — (Might remove this one, but threw in here for the moment – zoom25)
• Muddy — Opposite of clear. Hard to pick out individual instruments etc.
• Muffled — Sounds like it is being played through a pillow or similar, weak highs or upper mids.
• Musicality — Fluff term regarding a sense of ‘cohesiveness’ and ‘correctness’ in the sound of music.
• MAP — Stands for “Minimum Advertised Price” enforced by headphone manufacturers. Read on for more pricing information related to MAP.
• Monaural — (Compare with Binaural)A headset with a single speaker.
• Mini plug — A smaller and more common version of the full-sized jack. The 3.5mm (1/8″) mini plug was introduced by Sony in 1979 for its portable Walkman®. It’s widely used today for portable media players, although adapters are available for converting mini plugs to full-sized jacks and vice versa.
• Modular —  Modular means square and generally refers to modular RJ9 plugs. Most Plantronics amplifiers use modular ports.
• Multipoint Technology — Multipoint is also known as “multishifting.” Although all of our Bluetooth headsets can pair with up to four different devices, multipoint technology allows some Bluetooth headsets to switch active connections between two paired devices. Non-multipoint headsets can be actively connected to only one device at a time.
• Mute Alert — An audio alert that lets the user know when mute is turned off.

N

• Naturalness– Realism
• Neutral/Neutrality — Relatively flat frequency response, tends to be accurate with no exaggerations in any section.
• Nasal — Honky, a bump in the response around 600 Hz.
• Noise Cancelling — An electro-acoustic system which uses a microphone in the earpiece and an electronic circuit to produce a signal which is fed into the headphone which counter-balances and cancels outside/ambient noise to provide acoustic isolation.
• Neodymium magnets — Neodymium is one of several rare earth metals used in creating the small, high-strength magnets commonly used in headphone drivers.
• Noise attenuation — Noise attenuation describes any reduction of unwanted sound. Noise-canceling headphones achieve this by using a microphone to pick up outside noise and then actively reduce the noise by creating an out-of-phase signal. Noise-isolating headphones reduce noise passively by using extra layers of padding around the earcup or an in-the-ear design.
• Noise-isolating —Noise-isolating headphones use dense materials around the ear or in the ear to passively block out noise. Technically, all headphones offer some form of passive noise isolation, but headphones labeled as such are specifically designed for the job. They usually promote safer listening habits, since users often don’t have to turn the volume up as much to drown out external noise.

O

• Opaque — Not clear, lacking transparency.
• Open (headphone) — The back of the driver is open to the air. Generally causes headphones to have greater soundstage and detail but less bass impact.
• Open (sound attribute) — Sounds airy and with lots of space, generally describes highs and upper midrange.
• Output Impedance — The effective resistance seen by a load as it “looks back into” the output of an amplifier. The lower the output impedance of an amplifier, the more it shorts out (damps) the energetic reactions of the load.
• Op-Amp — An Operational Amplifier is technically an electronic amplification circuit with an inverting and non-inverting input and an output, ready to be configured to act in a variety of different ways using various methods. Commonly, Op-Amp is used to describe a type of integrated circuit chip that performs these functions.
• OPA 627 — An audio op-amp Previously a Burr-Brown, but now a Texas Instruments
• Optical — Optical, when used on the HeadRoom website, most often refers to a digital audio connection which uses light instead of an electricity to pass a signal. Optical cables (sometimes called Toslink cables) use a clear plastic fiber internally to pass the light on which the digital signal is carried. These connections have the advantage of not carrying an electrical signal and may help prevent ground loops and transfer of noise and are immune from RF interference. Unfortunately, optical cables can vary widely in quality; we recommend using higher quality optical cables for runs longer than three feet.
• OTL Tube Amps — OTL means “Output Transformer-less.” Tube amplifiers typically use transformers to convert the high-voltage/low-current signals at the tube output into the low-voltage/high-current signal needed to drive the speaker. OTL amps use capacitive coupling, or D.C. coupling instead.
• Omni-Directional — (Contrast with Directional)Usually applied to a microphone, when it is capable of receiving sounds equally from any direction.
• On-the-Ear — A style of headset that hangs from the ear. 
• Over-the-Head — The most common style of headset – with a headband that goes up and over your head. Typically available in monaural and binaural styles.
• Ohms — The unit of measurement for impedance.

P

• Piercing — Sharp peaks that make it difficult to listen, generally in the upper mid range and highs.
• PRaT — Pace, Rhythm, and Timing
• Presence Range — The presence range between 4kHz and 6kHz is responsible for the clarity and definition of voices and instruments. Increasing this range can make the music seem closer to the listener. Reducing the 5kHz content makes the sound more distant and transparent.
• Presence — A sense that the instrument in present in the listening room. Synonyms are edge, punch, detail, closeness and clarity. Adequate or emphasized response around 5 kHz for most instruments, or around 2 to 5 kHz for kick drum and bass.
• Puffy — A bump in the response around 500 Hz.
• Punchy — Good reproduction of dynamics. Good transient response, with strong impact. Sometimes a bump around 5 kHz or 200 Hz.
• Power Amplifier — A power amplifier increases the amount of energy in an audio signal from a low level to a power level high enough to drive a pair of speakers. Power amplifiers typically have a fixed gain (amount of amplification) and volume is controlled by a pre-amp or headphone amp prior to being sent to the power amp. Power amplifiers are typically rated in Watts delivered into 4 or 8 ohms. Typical power ratings for desktop speaker amplification is about 25-100 Watts into 8 Ohms. 750 Watts is about 1 horsepower.
• Power Supply — In audio, the circuitry that converts the A.C. wall voltage into usable D.C. supply voltages inside the device. “Stiff” power supplies are desirable and are those that change very little as the current demand from other circuits changes.
• Pace — Often assoc. with rhythm, a strong sense of timing and beat.
• PerSono™ — (Plantronics DSP Headsets)PerSono is a software suite designed to enhance communications over VoIP softphones.
• Plantronics — A headset manufacturer.
• Polaris — A range of headsets from Plantronics designed to work with specific models of phones that have a built-in amplifier. Typically Meridian and Norstar systems use this type of headset.
• Portable headphones —Portable headphones are generally small and lightweight for easy mobility. Some models are geared for certain activities, like exercising or wirelessly listening to music and answering calls from a Bluetooth-enabled cell phone.
• Pairing — Pairing refers to establishing a wireless connection between a headset and a phone. It is often used to describe the initial set up between a Bluetooth headset and phone.
• Pairing Mode — Indicates when a device is discoverable or looking to be discovered. Typical of BT situations. Indicated on Plantronics products by rapidly flashing lights.
• Passkey — Passkey refers to a password needed to connect a Plantronics Bluetooth headset to a Bluetooth device. For most Plantronics products, this passkey is 0000. Sometimes referred to as a passcode.

Q

• Quick Adjust™ —  Quick Adjust refers to a telescopic microphone boom that lets you place the microphone in the optimal position for speech recognition and clarity of sound in your conversations.
• Quick Disconnect — A small connector in the headset cord that allows the user to break away from a call to move around the office and reconnect without placing the caller on hold.

R

• Roll-off — When a headphone will roll off dB at certain frequencies.
• Rumble — (might remove this – zoom25).
• Range — The distance between the lowest and highest tones.
• Rich — See Full. Also, having euphonic distortion made of even order harmonics.
• Resonance — The characteristic of a physical systems ability to “ring.” A bell is resonant. Electrical circuits can also “ring” as in an oscillator, but resonant circuits can also be used to create filters. Reducing unwanted resonance when driving headphones is generally accomplished through damping.
• Round — High frequency rolloff or dip. Not edgy.
• Rhythm — The controlled movement of sounds in time.
• Remote Answering Platform — Used with Plantronics Wireless Headset Systems, this device allows you to answer the phone without returning to your desk to lift the receiver.
• Reversible — (Contrast with Convertible)A reversible headset can be worn with the speaker on either the left or right ear. The headset is designed to be easily adjustable to suit your preference.
• Radio frequency (RF) transmission — Most wireless headphones use radio frequency transmission to send audio information from the transmitter to the headphones. RF transmission gives headphones a greater range than IR transmission. Other devices, such as cordless phones and wireless routers, may operate in the same radio frequency, and can cause some possible interference.
• Receive — Your receive volume refers to the volume of what you hear. Increasing your receive volume will make the caller sound louder for you. It will not affect the way that your voice sounds to the caller.
• Reject Call — Function of headset which disconnects the call or sends the call to voice mail depending on the device
• Reset — Resetting your wireless headset can clear static and correct other acoustic issues. See our Knowledge Base on plantronics.com to find reset instructions for your headset.
• RJ9 — RJ9 is a standard modular plug on most corded telephones. RJ9 has four positions and four contacts (4P4C). Many Plantronics amplifiers also use this plug size.

S

• Soundstage — Ability of a headphone to place instruments to be perceived near and far.
• Sterile — Neutral; usually used with negative connotation.
• Strident — Harsh, Edgy.
• Supra-aural — Headphone that rests on the ear.
• Sub-bass — Sub-100hz frequencies that are more felt than heard.
• S/PDIF — S/PDIF stands for “Sony/Philips Digital Interconnect Format,” and is an industry standard specifying the hardware connections (RCA, BNC, or Toslink) and “data link layer” protocols for digital audio transfer in consumer electronics. It is a subset of a larger standard for digital audio transfer, IEC 60958, which is also known as the “AES/EBU” standard.
• Sealed — Sealed headphones are also called ‘closed-back’ headphones and are designed to block out environmental noise using a passive acoustic seal. Full size closed headphones provide about -10dB to -15dB of isolation, mostly in the higher frequencies. Smaller on-ear closed headphones provide somewhat less isolation dependent on their design and the shape of your ear. In-ear headphones are a closed design in which the ear-pieces seal in the ear canal providing about -23dB of outside noise attenuation and are the highest isolation of headphone type. Noise-cancelling headphones are typically sealed designs with battery-powered electronics to attenuate ambient noise better than a passive closed-back seal could provide.
• Self-powered (speakers) — Usually, computer speakers which contain their own power amplifier, take a line input, and have their own volume control. There are, however, very good self-powered speakers of all sizes and quality used by professionals and audiophiles alike.
• Solid State — A broad categorization of active electronic circuitry that use transistors of various types (NPN, PNP, FETs, J-FETs, and analog integrated circuits) to provide gain. Usually used to differentiate between vacuum tube-based designs.
• Square Wave Response — An audio test signal which alternates between two D.C. levels. Used to visualize the systems ability to pass a wide range of frequencies in proper time-alignment.
• Supra-aural — Literally meaning “on the ear,” supra-aural headphones rest against the outer ear and are generically termed earpad headphones. Ear-pieces are sometimes literally flat pads against the ear, but can also be shallow bowl-shaped, or deeper ear cups that are too small to fully surround the ear.
• Saturation — The point at which a magnetic tape is fully magnetized and will accept no more magnetization.
• Seismic — Very low bass that you feel rather than hear.
• Shrill — Strident, Steely.
• Sibilant (or Sibilance) — “Essy”, exaggerated “s” or “sh” sounds in vocals. Sibilant sounds carry most of their energy through the 4Khz to 8Khz range, but can extend to 10kHz, depending on the individual. Sibilance is often heard on radio.
• Smeared — Lacking detail; poor transient response, too much leakage between microphones; poorly focused images.
• Smooth — Easy on the ears, not harsh. Flat frequency response, especially in the midrange. Lack of peaks and dips in the response.
• Snap — A system with good speed and transient response can deliver the immediacy or “snap” of live instruments.
• Sizzly — See Sibilant. Also, too much highs on cymbals.
• Spacious — Conveying a sense of space, ambiance, or room around the instruments; stereo reverb; early reflections.
• Speed — A fast system with good pace gives the impression of being right on the money in its timing.
• Steely — Emphasized upper mids around 3 to 6 kHz. Peaky, non flat high frequency response. See Harsh, Edgy.
• Sturdy — Solid, powerful, robust sound.
• Sub-Bass — The audio frequencies between about 20Hz and 80Hz.
• Sweet — Not strident or piercing. Delicate. Flat high frequency response, low distortion. Lack of peaks in the response. Highs are extended to 15 or 20 kHz, but they are not bumped up. Often used when referring to cymbals, percussion, strings, and sibilant sounds.
• Sound Card — A sound card converts the digital signal your computer produces into a signal that can be played through speakers or headphones.
• Sound Enhancement System™ (SES) — (Plantronics)The Plantronics Sound Enhancement System lets you highlight bass or treble sounds for a fuller, richer tone. It’s used on the Plantronics Encore line of headsets.
• Soundguard™ — Plantronics SoundGuard Plus™ technology, ensures that loud tones are quickly reduced and that any transient ‘pops’ are instantly capped. Most importantly, SoundGuard Plus™ ensures that the normal, human voice remains natural and unchanged, delivering face-to-face clarity of communication to the call center environment.
• Standby-Time — (Contrast with Talk-Time)Standby is a mode of operation on a wireless (or cellular) phone that allows it to conserve power while not in use. ‘Stand By Time’ is usually the amount of time that headset system will need between charges – even if no calls are made or received.
• Single-sided cord — Single-sided cords extend from one earcup in a single cord, keeping it to the side and out of the way. Some headphones come with detachable single-sided cords that allow you to easily store your headphones, switch out the cord with different lengths, or replace damaged cords
• Speaker — A device that converts an electrical current into sound. Speakers usually consist of a number of drivers, such as woofers and tweeters, for reproducing a specific range of frequencies. Most headphones use tiny, scaled-down versions of big speakers to create sound.
• Sport headphones — Sport-style headphones are specially designed for active use. Most feature earbuds with ear clips, ear loops, or ear hangers for a secure fit, or a behind-the-neck band for an out-of-the-way design. Many also come in bright colors and have a waterproof or sweatproof coating that allows them to be washed by hand.
• Swivel earcups — Swivel earcups provide a comfortable fit that better conforms to the shape of an individual’s head. Vocalists and musicians also frequently use swivel earcups for single-ear monitoring so that they can listen through one side of the headphones while simultaneously hearing the external environment.
• Smart Lock — A screen lock/unlock capability based on proximity detection of a Plantronics Legend Bluetooth® headset.
• Smart Sensor Technology — These sensors detect whether or not you are the wearing the headset. Sensors are located in the headset body and speaker housing.
• Softphone —A software program for making telephone calls over the Internet using a general-purpose computer rather than dedicated hardware such as a standard desktop telephone.

T

• Texture — A perceptible pattern or structure in reproduced sound.
• Thick — A lack of articulation and clarity in the bass.
• Thin — Fundamentals are weak relative to harmonics; bass light.
• Tight — Good low frequency transient response and detail.
• Timbre — The tonal character of an instrument
• Timing — A sense of precision in tempo.
• Tinny — Narrowband, weak lows, peaky mids. The music sounds like it is coming through a telephone or tin can.
• Tone — The sound of definite pitch.
• Transient — The leading edge of a percussive sound. Good transient response makes the sound as a whole more live and realistic.
• Transparent — Easy to hear into the music, detailed, clear, not muddy. Wide flat frequency response, sharp time response, very low distortion and noise. A hear through quality that is akin to clarity and reveals all aspects of detail.
• Transistor — A small electronic device which can provide electrical signal gain in circuit construction. Manufactured using silicon or gallium arsenide semiconductor materials in negatively and positively dopes crystal layers in a variety of structural configurations. Mainly segregated into bipolar and field effect types.
• Tube Amplifier — An audio amplifier using vacuum tubes in its gain stages.
• Treble — The highest part of music and voice. See Highs. (Most often used when referring to the treble control on amplifiers).
• Tubby — Having low frequency resonances as if you’re singing in a bathtub.
• Talk-time — (Contrast with Standby-Time)The number of hours you can talk on your headset before it must be recharged.
• Three-Point Fit™ — (Plantronics TriStar Headset)This Plantronics technology provides four sizes of user-selectable earbuds and an adjustable receiver arm, so the headset can be customized to your preference. The headset is in contact with your ear in three places, each can be adjusted to match the uniqueness of your ear.
• Training Adapter — Our training adapter allows two headsets to connect to a single phone so supervisors can listen in with trainees. Ideal for getting new recruits up to speed as quickly as possible. Training adapters can be purchased separately from our accessories page
• Tru-Comfort™ — A combination of design and materials that have been developed to allow the ear to breath during prolonged use, and to eliminate issues arising from long term pressure or contact on the outer ear.
• Two Prong Adapter — Allows you to use a headset with your CAD COM, Key and other two-prong phone systems. Two prong adapters can be purchased separately from our accessories page.

U

• USB — USB stands for Universal Serial Bus and is a standardized interface designed primarily for personal computers as a peripheral control interface, but may be used in other devices like gaming consoles and handheld portable devices. The USB standard is controlled by the USB Implementer Forum, Inc which is a consortium of industry players including Apple, HP, NEC, Intel, and Microsoft.
• USB Adapter — A USB device that enables UC functionality.
• Upper Midrange (Upper Mids, High Mids) — The audio frequencies between 2 kHz and 6 kHz.

V

• Veiled – Like a silk veil is over the speakers. Slight noise or distortion or slightly weak high frequencies. Loss of detail due to limited transparency.
• Voice Tube — A voice tube carries sound from your mouth to a microphone that is housed in the ear cup of a headset. This design strategy produces headsets that can be manufactured at a significantly reduced cost – a saving that is reflected in the cost to the end-user. The downside is that the microphone can not make use of Noise Canceling technologies, and is therefore less suitable for noisy environments.
• VoIP — Voice over Internet Protocol. This is a technology that allows you to talk to others over the internet, rather than over phone lines
• Virtual surround sound — Headphones with this feature use sophisticated processing to fool your ears into thinking that sound is coming from multiple locations around you, instead of just two. Virtual surround sound headphones come in handy when you want a more private home theater experience, or when you don’t want your movie or music to disturb others.Some newer headphones have virtual surround sound built in, while others require an adapter to add this functionality. Most new receivers also offer this capability built into their headphone jack, like Silent Cinema on Yamaha receivers and Dolby’s Dolby® Headphone.
• Vechile Power Charger — Allows a headset to be charged in a vehicle, usually via the vehicle’s lighter socket. Abbreviated as VPC.
• Voice Alert — A recorded notification message that informs the user about a change in the state of the phone or headset (turned on or off, pairing status, incoming call, etc.)
• Voice Prompt — A recorded notification message that asks the user to take action, such as accept or reject an incoming call.

W

• Warm — Good bass, adequate low frequencies, adequate fundamentals relative to harmonics. Not thin. Also excessive bass or mid bass. Also, pleasantly spacious, with adequate reverberation at low frequencies. Also see Rich, Round. Warm highs means sweet highs.
• Wet — A reverberant sound, something with decay. Opposite of Dry.
• Weighty — Good low frequency response below about 50 Hz. A sense of substance and underpinning produced by deep, controlled bass. Suggesting an object of great weight or power, like a diesel locomotive.
• Woolly — Loose, ill-defined bass.
• Wireless — Wireless headphones replace the wire with an alternative method for getting the audio signal to the headphones. Most commonly this is done with analog modulation of 900MHz radio frequency transmission, but digital modulation of 900MHz RF, Bluetooth, KLEER, and infra-red systems are also available.
• Windscreen — A protective covering for headset microphones that mitigates wind noise to enhance microphone performance.

X

Y

• Y TRAINING CABLE — A cable that allows two headsets to be connected to one phone, enabling two people to listen to the same call (for training purposes).

Z

• Zitternd– Trembling