Audio headset
A headset is a combination of headphone and microphone. Headsets connect over a telephone or to a computer, allowing the user to speak and listen while keeping both hands free. They are commonly used in customer service and technical support centers, where employees can converse with customers while typing information into a computer. They are also common among computer gamers and let them talk with each other and hear others while using their keyboards and mice to play the game.
Types
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 re-assembling various parts. There are also under-the-chin headsets similar to the headphones that stenographers wear.Neckband styles
Neckband headsets 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 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
; 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 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 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 device, however many phones, including modern IP phones, still do not have discrete circuitry for switchhook operation.
Computer
Computer headsets generally come in two connection types: standard 3.5 mm and USB connection. General 3.5 mm computer headsets come with two 3.5 mm connectors: one connecting to the microphone jack and one connecting to the headphone/speaker jack of the computer. 3.5 mm computer headsets connect to the computer via a sound card, which converts the digital signal of the computer to an analog signal for the headset. USB computer headsets connect to the computer via a USB port, and the audio conversion occurs in the headset or in the control unit of the headset.Gaming headsets for computers are specifically designed for gaming and provide some additional features that can be beneficial for gamers. These features include game-specific sound modes, aesthetic designs inspired by popular games or themes, detachable microphones, and RGB lighting.
Mobile phone
Mobile phone headsets are often referred to as handsfree. Older mobile phones used a single earphone with a microphone module connected in the cable. For music-playing mobile phones, manufacturers may bundle stereo earphones with a microphone. There are also third-party brands which may provide better sound quality or wireless connectivity.Mobile headsets come in a range of wearing-styles, including behind-the-neck, over-the-head, over-the-ear, and lightweight earbuds. Some aftermarket mobile headsets come with a standard 2.5 mm plug different from the phone's audio connector, so users have to purchase an adapter. A USB headset for a computer also cannot be directly plugged into a phone's or portable media player's micro-USB slot. Smartphones often use a standard 3.5 mm jack, so users may be able to directly connect the headset to it. There are however different pin-alignment to the 3.5mm plug, mainly OMTP and CTIA, so a user should find out which settings their device uses before buying a headphone/headset.
Many wireless mobile headsets use Bluetooth technology, supported by many phones and computers, sometimes by connecting a Bluetooth adapter to a USB port. Since version 1.1 Bluetooth devices can transmit voice calls and play several music and video formats, but audio will not be played in stereo unless the cell phone or media device, and the headset, both have the A2DP profile.