Headphone Terminology

Monaural (Mono): Designates single source sound reception. Mono sound can be described as a sound that seems to come from one direction only. Mono headphones should be used with mono sound source products such as cassette player/recorders and record players. Mono headphones should not be used with stereo sound source products such as PCs, televisions or portable CD players. Using mono headphones with a stereo sound source can create an electrical short circuit in one of the stereo channels which may damage connected equipment. Using mono headphones with a stereo sound source also limits the audibility. The listener only hears out of one of the ear cups/pieces.

Stereo: Designates sound reception to both ears. Stereo sound can be described as a sound that is 3 dimensional or sound that comes from all directions. Stereo headphones should be used with stereo sound source products such as PCs, televisions and portable CD players. Stereo headphones are not meant for use with mono sound source products such as cassette player/recorders and record players.

Please Note: Mono/stereo switchable headphones are available. This technology allows you to switch from mono to stereo at the flip of a switch. This feature enables the use of headphones with all sound source products. Simply flip the switch to mono for use with cassette players/recorders and record players and to stereo for use with PCs, televisions and portable CD players.

Lab Pack: Many headphones that are stored in a carrying case and allow, for example, 24 individuals to access the same sound source.

(A) Listening Center: Listening centers are available with or without a sound source; with or without a jack box; with or without a carrying case, and with or without a remote control. All listening centers include headphones. The number of headphones differ and range in number from 4 headphones to 24 headphones.

(B) Jack Box: A box which allows multiple headphones to be connected to the same sound source. Jack boxes may be purchased with various headphone positions (number of headphones you are able to connect to the jack box at the same time) such as 6 position or 8 position. Jack boxes are also available with or without volume control. If you purchase headphones with volume control you would not need volume control on the jack box. If you purchase headphones without volume control you would want to purchase a jack box with volume control.

 HEADPHONE/HEADSET BUYING GUIDE

 

What is a headphone?

Headphones are devices that allow people to listen to audio without disturbing people nearby. They go in or over the ears so sound travels into people's ears instead of the space around them.

 

Difference between a headphone and a headset

There are two main groups of headphones: with a microphone (headset) and without (headphone). The headphones for with a microphone are in demand for uses where voice response is required, such as with voice response software, Skype, etc. Headphones without a microphone are used for listening to audio only in such things as computers, CD players, tablets, MP3 players and more. NOTE- Not all headsets (with mic) will work with cell phones and tablets.

 

Headset	Headphone
- Headphone with Microphone - For audio and voice - Used in computers, tablets, mobile devices	- Headphone - For audio only - Used in computers, tablets, mobile devices, MP3 players, CD players, cassette players, record players, etc.

 

 

 

 

 

 

 

 

 

 

 

There are three basic styles of headphone: Over Ear, On Ear and In Ear. For more frequent use by multiple users a deluxe headphone will likely be more suitable. Deluxe headphones are rugged pieces of equipment that are meant to be used often for long periods of time by multiple users. Choose a personal headphone for a more light-weight option. For individual use a personal or ear bud style headphone will also be suitable.

 

Over Ear Deluxe	On Ear Personal	In Ear Ear Bud
- Fully cover the ear - Usually extremely rugged construction - For heavy use setting - For long term wear - Ideal for grades K – 12	- Placed on the ear - Can be more or less rugged depending on brand - Perfect for individual use - For long term wear - Ideal for grades K – 12	- Placed in the ear - Less rugged than other styles - Perfect for individual use - For short term wear - Ideal for grades 5 – 12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stereo or Mono

Stereo headphones play back sound from two separate independent channels, a left channel and a right channel. Mono Headphones (also called monaural headphones) are headphones which can only play sound from a single channel. It is very important to determine if your audio source is stereo or mono. Using the wrong headphone will cause improper play back or could ultimately ruin your audio source. For example if a stereo headphone is plugged into a mono source, you will only get sound from one ear cup. When a mono headphone is plugged into a stereo source a temporary short circuit is created with one of the sound channels. Although you will get sound from both ear cups, it will only be one channel of sound opposed to 2. Extended use of a mono headphone in a stereo source could result in a permanent short circuit of one of the sound channels. There are some headphones on the market that are Stereo/Mono Smart and will automatically determine the type of audio signal and play it back accordingly without the worry of compatibility.

Stereo audio sources include most: computers, CD players, mobile devices, tablets, etc.

Mono audio sources include most: cassette players, record players, etc.

 

Type of plugs

The plug choice will depend on what you are plugging your headphone into. There are 4 types on plus: TRRS, 3.5mm, ¼" or USB.

 

TRRS – 3.5mm Headphone/Mic	3.5mm (aka 1/8") Plug	¼" Plug	USB Plug
For use with tablets, iPads, mobile phones and computers. TRRS plug combines the headphone and microphone function in a single plug.	For use with most: computers, CD players, tablets, mobile devices, and any unit with a 3.5mm or 1/8" headphone jack.	For use with most: Jack boxes, cassette players, record players, musical keyboard and any unit with a ¼" headphone jack.	For use with computers

 

Technical specifications explained

 

• Frequency response
• Impedance
• Sensitivity

 

The frequency range (amplitude-frequency characteristic) parameter, is considered by many as one of the most important. However, it is not always well understood. The amplitude-frequency characteristic (AFC) shows the dependence between the volume of the sound and its frequency in the form of a curve. The flatter this curve, the more neutral the sound of the headphone. In practice, producers show their products on the frequency range in which the frequency response curve of the most linear. The numbers of the upper and lower border of this range will not say anything to the consumer about the nature of the curve, and hence it makes it difficult to judge the quality of the sound basing solely on this parameter.

 

Sensitivity is a measure of how effectively an earpiece converts an incoming electrical signal into an audible sound. This indicates how loud the headphones will be for a given electrical drive level. The sensitivity of headphones is usually between about 80 and 125 dB/mW

Impedance - Headphones are available with low or high impedance (typically measured at 1 kHz). Low-impedance headphones are in the range 16 to 32 ohms and high-impedance headphones are about 100-600 ohms. As the impedance of a pair of headphones increases, more voltage but less current is required to drive it, and the loudness of the headphones for a given voltage decreases. Impedance of newer headphones has generally decreased to accommodate lower voltages available on battery powered portable electronics. This results in headphones that can be more efficiently driven by battery powered electronics.

Types of Ear Cushions

There are three basic types of ear cushions: Foam, Leatherette and Vinyl. The difference between these options is for easy of cleaning or replacement, comfort and noise reduction.

Foam – traditionally found on personal, on-ear style headphones. Foam cushions can't be cleaned very easily. Ideal when headphones are for use by a single person. Foam ear cushions can usually be easily and inexpensively replaced. Foam ear cushions do not offer any additional insulation from outside noise. Foam ear cushions are relatively comfortable and can be worn for extended periods.

Vinyl – found on both personal, on-ear and deluxe, over-ear style headphones. Vinyl cushions can be cleaned very easily. Vinyl ear cushions can be replaced. Vinyl ear cushions offer some additional insulation from outside noise by way of foam within the vinyl acting as an insulator to outside noises. Vinyl ear cushions are moderately comfortable.

Leatherette - found on both personal, on-ear and deluxe, over-ear style headphones. Leatherette cushions can be cleaned very easily. Leatherette ear cushions can be replaced. Leatherette ear cushions offer additional insulation from outside noise by way of foam within the leatherette acting as an insulator to outside noises. Leatherette ear cushions are extremely comfortable and can be worn for extended periods.

 

Cleaning Headphones

To clean most headphones, use a non-abrasive liquid cleaner such as peroxide. Dampen a cotton cloth by dipping it into the liquid. Wring the cloth to ensure that it is not too wet. Unplug the headphones then gently wipe the cloth over them, taking care not to saturate the headphones. Too much liquid will destroy the headphones, especially if drops find their way inside the tiny sound holes of the headphones. A cotton cloth should be fine for removing dirt and debris, but if a slightly more abrasive scrubber is desired, use nylon netting or even a toothbrush, just be sure that it is not saturated or dripping when you begin scrubbing.span>

 

If the headphones have a protective foam covering (another great hiding spot for germs) remove these if possible and drop them into the bowl of hydrogen peroxide. Allow them to sit there for a few moments, then remove and air dry. Put them back on the headphones only when they are completely dry. Use the cloth to completely wipe down the headphones, from the ear pieces, down the cord.

 

Many headphones have replacement ear cushions. These ear cushions can be replaced between users or as needed. Also there are hygienic disposable ear cup covers that can be used between users to limit exposure to germs and bacteria.

 

Types of Headphone Accessories

What it is	What it looks like	What it is used for
Hygienic Ear Cushion Covers		Disposable ear cushion covers designed to be replaced after each use so users are limited to exposure to germs and bacteria.
Replacement Ear Cushions		Ear cushions that replace original cushions that came with the unit.
Audio Safe(TM) Control Cable		Limits the volume delivered to a headset from any audio source to protect the listeners hearing.
Splitters		Allows you to connect 2 headphones to one audio source.
Jack boxes		Allows you to connect up as many as 10 headphones to one audio source. Available with and without individual volume controls.
UV Cleaning Devices		Device that uses UV rays to clean headphones from germs and bacteria.
Adapters		Available in 1/4" female to 1/8" male and 1/8" female to ¼" male. Allows you to use a plug that is not compatible with an audio source. For size only. Can't mix and match stereo and mono signals.

 

Headphone Compatibility

Selecting the headphone that is compatible with your audio device will be based on the stereo/mono compatibility and they plug type. The headphone style, ear cushions, type of cord, etc will not be a factor with compatibility.

 

Device (applicable to most)	Stereo/Mono	Type of Plug
Tablet, Mobile Devices, Computers (with single headphone/mic plug)	Stereo	TRRS
Computer (check compatibility of operating system to headphone)	Stereo	USB or 1/8" (3.5mm) or TRRS (depending on mic jack)
iPad™/Tablet	Stereo	1/8" (3.5mm) or TRRS (depending on jack)
Phone/Mobile Device	Stereo	1/8" (3.5mm) or TRRS (depending on jack)
CD Player/Stereo	Stereo	1/8" (3.5mm)
TV	Stereo	1/8" (3.5mm)
Record Player	Mono	¼"
Cassette Player	Mono	¼"

*Please be sure to check your device before making selections. Information above is based on general standards. Check to see if device has stereo or mono output and check to see the size/type of the audio jack; 10/4" 1/8: (3.5mm) or USB).

 

Also note that compatibility of the headphone is based solely on the device and not the software or audio. For example, the type of curriculum software being used on a computer will not affect the compatibility. The actual operating system and physical audio inputs on the device with determine what kind of headphone is needed.