Telephone headsets generally use
loudspeakers with a narrower
frequency range than those also used for entertainment. Stereo computer headsets, on the other hand, use 32-ohm speakers with a broader frequency range.
Mono and stereo Headsets are available in single-earpiece and double-earpiece designs. Double-earpiece headsets may support
stereo sound or use the same
monaural audio channel for both ears. Single-earpiece headsets free up one ear, allowing better awareness of surroundings.
Telephone headsets are monaural, even for double-earpiece designs, because telephone offers only single-channel input and output.
Microphone style The microphone arm of headsets may carry an external microphone or be of the voice tube type. External microphone designs have the microphone housed in the front end of the microphone arm. Voicetube designs are also called internal microphone design, and have the microphone housed near the earpiece, with a tube carrying sound to the microphone. Most external microphone designs are of either
omnidirectional or
noise-canceling type. Noise-canceling microphone headsets use a
bi-directional microphone as elements. A bi-directional microphone's receptive field has two angles only. Its receptive field is limited to only the front and the direct opposite back of the microphone. This creates an "8" shape field, and this design is the best method for picking up sound only from a close proximity of the user, while not picking up most surrounding noises. Omni-directional microphones pick up the complete 360-degree field, which may include much extraneous noise.
Headband styles Standard headsets with a headband worn over the head are known as
over-the-head headsets. Headsets with headbands going over the back of the user's neck are known as
backwear-headsets or
behind-the-neck headsets. Headsets worn over the ear with a soft ear-hook are known as
over-the-ear headsets or
earloop headsets. Convertible headsets are designed so that users can change the wearing method by reassembling various parts. There are also
under-the-chin headsets similar to the headphones that stenographers wear.
Neckband styles Neckband headsets (also called neckband earphones or neckband ear sets) have grown in popularity. These are a modern design where the band rests around the neck rather than over the head or directly on the ear. This design improves comfort during prolonged use keeps weight off the ears, and allows the band to house larger batteries, vibration motors and in-line controls. Neckband headsets are widely used in Bluetooth wireless models, offering a balance between portability and battery life.
Earpiece styles Headsets earpieces may be for either one or both ears. They generally come with one of 3 styles: •
in-the-ear -- these have a small speaker contained in an earbud that fits inside the outer portion of the ear canal. •
on-the-ear -- these have a flat speaker (often cushioned) that sits on the external ear. •
around-the-ear -- these have a larger, cushioned earpad that fits around the external ear and sits against the head, to exclude more external noise.
Telephone Telephone headsets connect to a
fixed-line telephone system. A telephone headset functions by replacing the
handset of a telephone. Headsets for standard corded telephones are fitted with a standard
4P4C commonly called an RJ-9 connector. Headsets are also available with 2.5mm jack sockets for many DECT phones and other applications. Cordless
bluetooth headsets are available and often used with
mobile telephones. Headsets are widely used for telephone-intensive jobs, in particular by
call centre workers. They are also used by anyone wishing to hold telephone conversations with both hands free. ; Headset compatibility and pin alignment Not all telephone headsets are compatible with all telephone models. Because headsets connect to the telephone via the standard handset jack, the pin-alignment of the telephone handset may be different from the default pin-alignment of the telephone headset. To ensure a headset can properly pair with a telephone, telephone adapters or pin-alignment adapters are available. Some of these adapters also provide a mute function and switching between handset and headset. ; Telephone amplifiers For older models of telephones, the headset microphone
impedance is different from that of the original handset, requiring a telephone amplifier to impedance-match the telephone headset. A telephone amplifier provides basic pin-alignment similar to a telephone headset adapter, but it also offers sound
amplification for the microphone as well as the loudspeakers. Most models of telephone amplifiers offer volume control for the loudspeaker as well as a microphone, mute function and switching between handset and headset. Telephone amplifiers are powered through batteries or
AC adapters. ; Quick-disconnecting cable Most telephone headsets have a Quick Disconnect (QD) cable, allowing fast and easy disconnection of the headset from the telephone without having to remove the headset. ; A
Handset lifter is a device that automatically lifts or replaces a
handset off/on a
telephone. It is usually connected to a
wireless headset and allows cordless headset use on technically primitive desk phones. Some phones only have a mechanical means of switchhook operation. The lifter allows cordless headsets to be used remotely with such phones. The phone user presses the appropriate headset button to either answer a call or terminate a call. The headset's base station's interface with the handset lifter will take the appropriate action - lift or replace the handset. The use of a handset lifter is considered archaic by most technical professionals. Technology from decades ago eliminated the need for such a device; however, many phones, including modern IP phones, still do not have discrete circuitry for switchhook operation. == Computer==