 |
This article may require copy-editing for grammar, style, cohesion, tone or spelling. You can assist by editing it. (February 2008) |
 |
This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (February 2008) |
 |
This article or section has multiple issues. Please help improve the article or discuss these issues on the talk page.
|
|
|
This article may contain material not appropriate for an encyclopedia. Please discuss this issue on the talk page. (May 2008) |
A headset is a headphone combined with a microphone. Headsets provide the equivalent functionality of a telephone handset with hands-free operation. Headsets typically have only one speaker like a telephone, but also come with speakers for both ears.[1] They have many uses including in call centers and other telephone-intensive jobs and for personal use at the computer to facilitate comfortable simultaneous conversation and typing.
Contents |
Types of headset
Headsets can come in single-earpiece and double-earpiece designs. Single-earpiece headsets are known as monaural headsets. However, double-earpiece headsets come in both stereo type (two channels of audio signal, one for each earpiece) or binaural type (the same audio channel for both ear-pieces).
Professional users may choose to wear monaural headsets because they free up one ear, so they can be more conscious of their work surroundings. Telephone headsets come in only monaural type for double-earpiece designs because telephone offers only single-channel input and output, so all double-earpiece telephone headsets are binaural.
However, for computer or other audio applications, where the sources offer two-channel output, stereo headsets are the norm. Telephone headsets generally use 150-ohm[2] loudspeakers with a narrower frequency range, so sound outside the voice band is less audible to reduce background noise. Stereo computer headsets, on the other hand, use 32-ohm loudspeakers which have a much broader frequency range, and is more suitable of music listening.
External microphone vs. microtube
The microphone arm of headsets comes in external microphone type and voicetube type. External microphone designs have the microphone housed in the front end of the microphone arm, inside a microphone capsule. Voicetube designs are also called internal microphone design, and have the microphone housed near ear-piece. The sound travels through the tube to the hidden microphone.
Noise-canceling microphone vs. omni-directional microphone
External microphone design also comes in two major types: omni-directional and noise-canceling. Noise-canceling microphone headsets use a bi-directional microphone as elements.[3] 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 create an "8" shape field, and this design is the best method for picking up sound only from a close proximity of the user, meanwhile not picking up most surrounding noises. Bi-directional microphones work better than uni-directional microphones because uni-directional microphones also pick up some of the sound 90 degrees to the desired angle. Omni-directional microphones pick up the complete 360-degree field, but also most of the surrounding noises. In some instances, when a higher sensitivity is required for the microphone, or when the sound source is further away from the microphone, an omni-direction microphone is the preferred choice. Almost all voicetube designs use an omni-directional microphone.
Different styles of headsets
Standard headsets with a headband worn over the head are known as over-the-head headsets. Headsets with headband 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 or earloop headsets. Convertible headsets are designed so that users can change the wearing method by re-assembling various parts.
Telephone headsets
Telephone headsets connect to a fixed-line telephone system. A telephone headset functions by replacing the handset of a telephone. All telephone headsets come in a standard 4P4C commonly called an RJ-9 connector.
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.
Telephone amplifiers
For older models of telephones, the headset microphone impedance is different from that of the original handset, requiring a telephone amplifier to pair with the telephone headset. A telephone amplifier provides basic pin-alignment similar to a telephone headset adaptor, but it also offers sound amplification for the microphone as well as the loudspeakers. Most models of telephone amplifiers offer volume control for loudspeaker as well as microphone, mute function and headset/handset switching. Telephone amplifiers are powered through batteries or AC adaptors.
Quick disconnecting cable
Most telephone headsets come with a Quick Disconnect (QD) cable, allowing for fast and easy disconnection of the headset from the telephone. This allows the user to disconnect from the telephone, without having to physically remove the headset.
Computer headset
Computer headsets generally come in two connecting types, standard 3.5 mm & USB connection. General 3.5 mm computer headset comes with two 3.5 mm connectors, one connecting to microphone jack (line-in) and one connecting to speaker jack (line-out) of the computer. 3.5 mm Computer Headsets connect to the computer via a soundcard - which converts the digital signal of the computer to analog signal for the headset. Depending on the quality of the soundcard, the sound quality of 3.5 mm connection generally is not as good as a USB connection. USB computer headset connects to the computer via USB ports, and the audio conversion occurs in the USB PCBA located in the headset or in the control unit of the headset.
3.5 mm computer headset
Usually 3.5 mm headsets are much cheaper, and this is reflected in the quality. For very basic communication, or entry level users, a 3.5 mm headset is more than sufficient. Connection is simple and compatibility is high. Virtually any device can be connected with a standard 3.5 mm jack, meaning users can connect the speaker (line-out) plug to a MP3 player or a CD Player with a 3.5 mm jack without any problems. Users can also connect the microphone (line-in) plug to any digital recording device with a 3.5 mm jack as well. However, the sound quality is marginal for these types of headset. Even coming from big brand names like Logitech, one cannot expect high-end quality from this type of product.
USB headset
USB headsets are more expensive, but the sound quality is better.[citation needed]
Headsets with USB connection
Headsets with USB connection are computer headsets with a standard 3.5 mm headset bundled with a USB adaptor. One end of the USB adaptor is a standard USB plug, but the other end is a pair of 3.5 mm jacks where the 3.5 mm computer headset is connected. The benefit of using this type of solution is that users can just buy the USB adaptor to use with their existing 3.5 mm headset, or they can use their existing multimedia speakers or desktop microphone. However the sound quality of this type of solution is much lower than a standard Direct USB Headset, plus the adaptor and all the cables makes this solution very cumbersome.
Direct USB headsets
Direct USB Headsets usually have a digital volume controller which includes the USB module. This solution is usually higher quality, as the direct connection minimizes interference as well as length of path.
With most Operating Systems USB Headsets are plug-and-play, and no drivers are required. However, depending on the extra features the headset offers, some may require extra software installation. In addition to sound quality, a benefit of any USB headset is Interactivity, meaning users in addition to getting audio signals from the computer, users can actually control the computer using the headset. There are some products in the market which users can use the USB headset to start up Skype, and control various functions of the Instant Messenger (IM) Application by only using the headset. [4]
Mobile phone headsets
Mobile (Cellular) Phone Headsets are most often referred to as Mobile Handsfree. Most mobile phones come with their own handsfree in the form of a single earphone with a microphone module connected in the cable. However, as music-playing mobile phones are becoming the norm, most manufacturers will bundle stereo earphones with a microphone for MP3 listening. There are brands which offer mobile headset outside of the mobile phones developer. The main reason for this is either for better sound quality or higher convenience in the form of wireless solutions.
High quality mobile headsets come in both earbud-wearing style, as in the case of Jabra or Shure, and over-the-head-wearing style, as in Plantronics. Both types of headsets offer advantages, as earbuds are better in mobility and over-the-heads are more comfortable. Most after-market mobile headsets come in a standard 2.5 mm plug. So users have to purchase an additional adaptor for their mobile phones. Smartphones often use a standard 3.5 mm jack, so users may be able to directly connect the headset to it. However, brands like Sony Ericsson, Nokia or Motorola have very different headset jacks now. These adaptors are relatively cheap and can be purchased at any mobile accessories store. Users should be aware that they should bring their telephone to test the headset, as 2.5 mm plugs may still have some differences in its pin-setting, and are not 100% universal.
As for Wireless Mobile Headsets, most of them now use Bluetooth technology, as the advantage of using Bluetooth is that users do not need to add an extra transmitter in the mobile phone. Bluetooth audio transmission is relatively stable now, and most headsets are compatible with most mobile phones. The version 2.0 is the most compatible version now, with features like stereo transmission for music listening in A2DP profile.
Wireless headsets
Wireless headsets are quickly becoming a new trend for both business and consumer communications. There are a number of solutions for wireless, and they usually differ according to application and power-management.
DECT wireless headsets
DECT(Digital Enhanced Cordless Telecommunication] is one the most common standards for cordless telephones.[5] It uses 1.88 to 1.90 GHz RF (European Version) or 1.92 to 1.93 GHz RF (US Version), as the frequency bandwidth. Different countries have regulations for the bandwidth used in DECT, but most have pre-set this band for wireless audio transmission. The most common profile of DECT is GAP (Generic Access Profile), which is used to ensure common communication between base station and its cordless handset. This common platform allows communication between the two devices even if they are from different manufacturers. For example, a Panasonic DECT base-station theoretically can connect to a Siemens DECT Handset. Based on this profile, developers such as Plantronics or Jabra have launched wireless headsets which can directly pair with any GAP-enable DECT telephones. So users with a DECT Wireless Headset can pair it with their home DECT phones and enjoy wireless communication.
2.4 GHz wireless headsets
Because DECT specifications are different between countries, developers who use the same product across different countries have launched wireless headsets which use 2.4GHz RF as opposed to the 1.89 or 1.9 GHz in DECT. Almost all countries in the world have the 2.4 GHz band open for wireless communications, so headsets using this RF band is sellable in most markets. However, the 2.4 GHz frequency is also the base frequency for many wireless data transmission, ie. WLAN, Wi-Fi, Bluetooth..., the bandwidth may be quite busy, so using this technology may be more prone to interference.
Because 2.4 GHz Wireless Headsets cannot directly "talk" to any standard cordless telephones, an extra base-unit is required for this product to function. Most 2.4 GHz Wireless Headsets come in two units, a wireless headset and a wireless base-station, which connects to your original telephone unit via the handset jack (similar to how telephone headsets are connected to a fixed-line telephone suggested in section 1 of this article). The wireless headset communicates with the base-station via 2.4 GHz RF, and the voice signals are sent or received via the base unit to the telephone unit. This type of solution is more primitive as more connection is required, however it is also highest in compatibility, as it will fit with almost all types of telephones in the market. An extra note is that some solutions will also offer an automatic Handset Lifter, so the user can wirelessly lift the handset off the telephone by pressing the button on the wireless headset. Jabra (previously known as GN Netcom) has some excellent solutions in 2.4 GHz wireless products.
Bluetooth wireless headsets
 |
This section may require cleanup to meet Wikipedia's quality standards. Please improve this section if you can. (September 2008) |
Most users have heard about Bluetooth, and although this technology was designed originally for a much wider application, it has today become largely for voice transmission (a notable exception to this would be the use of Bluetooth in the Nintendo Wiimote). The reason for this general exclusivity is because of the power/range settings of Bluetooth. Bluetooth uses 2.4 GHz RF, similar to WLAN or Wi-Fi; however, by default it is set for a very close proximity usage for power consumption benefits. This deficiency for a longer-range coverage made bluetooth technology un-desirable for data transmission. As nowadays, more and more mobile phones come equipped with bluetooth, this technology has become a common wireless profile for wireless mobile phone headsets only.
When choosing a Bluetooth headset users should be aware that bluetooth headsets come in different types as well. Standard bluetooth headset's using version 1.0 or 1.1 are often a single-side monaural earpiece, which can only access the Headset/handsfree profile of Bluetooth. Depending on the phone's operating system, this type of headset will either play music at a very low quality (because the phone is converting it into a voice signal) or will be unable to play music at all (because the phone cannot perform such a conversion). Users who need a stereo-music playing Bluetooth headset should look for a headset with the A2DP profile.[6] Users should note that some A2DP-equipped headsets will automatically de-activate the microphone function during music-listening, so if these headsets are paired to a computer via bluetooth connection, the headset may either disable the stereo function or the microphone function.
Bluetooth wireless desktop solutions
Some developers have offered complete desktop solutions using Bluetooth technology. With a base-station that connects via cables to the fixed-line telephone and also the computer via soundcard, users with any bluetooth headset can pair their headset to the base-station, hence enabling them to use a single headset for both fixed-line telephone and computer VoIP communication. This type of solution, when used together with a multiple-point bluetooth headset enables user to use a single bluetooth headset to communicate in Telephone/Computer/Mobile.
There are now Bluetooth office headsets that incorporate Class 1 Bluetooth into the base station so that when using with a Class 1 Bluetooth headset, the user can get a greater distance from the phone or computer; generally around 100 feet compared to the 33 feet of Class 2 Bluetooth, which is what most Bluetooth headsets run on. The headsets that come with these base stations connect to cell phones via Class 2 Bluetooth, so you still get the same 33 foot range from your cell phone.
History
The first-ever headset was invented in 1910, by a Stanford University student named Nathaniel Baldwin.[7] However, Baldwin's design was ahead of his time, as he wasn't able to interest anyone in mass producing this innovative communication tool. Not until during the World War I did the US Army purchase 100 headsets for their pilots. Hence the early usage and markets for headsets were mainly for aviation purposes. In fact, Plantronics was started by two pilots,[8] and their main goals were to develop headsets which are lightweight and comfortable for pilots and subsequently general users.
Gallery
|
|
This section looks like an image gallery. Wikipedia policy discourages galleries of random images of the article subject; please edit or remove the section accordingly, moving freely licensed images to Wikimedia Commons if not already hosted there. |
 Typhoons "Jetswitch". The new technology automatically re-routes the sound from speaker to headset. |
 A Goldendance MGD-01 bone conduction headset. |
 A Plantronics Audio90 headset. |
 A wired headset for the Xbox 360. |
 An Xbox 360 Wireless Headset at TGS 2006 |
 A SonyEricsson Bluetooth headset. |
References
 |
Wikimedia Commons has media related to: Headsets |
- ^ Definition of Headset http://www.pcmag.com/encyclopedia_term/0,2542,t=headset&i=44185,00.asp
- ^ Telephone Headset Loudspeaker Impedance http://universalteleplaste.com/153d.htm
- ^ Directionality of Microphone by Webster Online http://www.websters-online-dictionary.org/mi/microphone.html
- ^ Blog posting by TMCNET
- ^ Definition of DECT by PC Magazine http://www.pcmag.com/encyclopedia_term/0,2542,t=DECT&i=41055,00.asp
- ^ Bluetooth A2DP Explained by PC Authority http://www.pcauthority.com.au/feature.aspx?CIaFID=1425
- ^ History of Nathaniel Baldwin http://historytogo.utah.gov/salt_lake_tribune/history_matters/070801.html
- ^ History of Plantronics http://www.plantronics.com/north_america/en_US/press/heritage.jhtml
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
