Headphones Benefits and Limitations

Headphones are a pair of small loudspeakers, or less commonly a single speaker, with a way of holding them close to a user’s ears and a means of connecting them to a signal source such as an audio amplifier, radio or CD player. They are also known as earphones, earbuds, stereophones, headsets or, colloquially cans. In the context of telecommunication, the term headset is used to describe a combination of headphone and microphone used for two-way communication, for example with a messenger telephone.

Types of headphones:
There are many different types of headphone designs, with the listening situation and the needs of the listener determining what type of headphone will be used.

Earcup headphones

Earcup headphonesEarcup or on-ear headphones rest on the exterior of the ear and were the earliest headphone form designed. The housing, or earcup, of an earcup headphone will be either open or closed. Open headphones, sometimes marketed as “open air” headphones, have an open grille on the back of the earcup, exposing the driver to the outside and allowing sound waves to propagate away from the ear freely. This backing type does not isolate the listener from outside sounds; in addition, sound through open headphones can be heard by others in the vicinity of the user. They usually have less distortion due to the lack of earcup resonance. Closed headphones have a sealed backing, which attenuates sound waves propagating away from the ear. As a result, listeners away from the headphones cannot hear the produced sound easily. In addition, sound from outside is attenuated by the sealed backing, providing a level of isolation to the listener. A sealed chamber is often claimed to have the negative effect of distorting sound in certain frequencies due to resonances within the earcup housing, however, bass frequencies are stronger in a sealed chamber headphone design.

In-ear headphones/Earbuds

Earbuds / earphones Earbuds or earphones are headphones of a smaller size that are placed directly outside of the ear canal, but without fully enveloping it. They are generally inexpensive and are favored for their portability and convenience. However, due to their inability to provide isolation, they are not capable of delivering the same dynamic range offered by many full-sized headphones and canalphones for a given volume level. As a result, they are often used at higher volumes in order to drown out noise from the user’s surroundings, which increases the risk of hearing-loss. During the 1990s and 2000s, earbuds became a common type bundled with personal music devices.

Smokin Buds Earbuds by Skullcandy with Speaker Diameter: 9mm

 

Headset (telephone/computer)

High Quality Sound Technology. High Definition and Dynamic Sound with Micro-HD Driver Unit.

Typical example of a headset used for voice chats. 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. They have many uses including in Call centres and other telephone-intensive jobs and for personal use at the computer to facilitate comfortable simultaneous conversation and typing.
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).
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.

Telephone headsets

The Phonapart Telephone recorder (Auomatic 2 WAY )simply plugs into any phone line.

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.
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.

Future of Westbury’s Victorian swimming pool is to be discussed at a public meeting.

This fantastic 15ft Swimming pool from Intex is ready to use within 15 Minutes!

The meeting will take place at The Laverton, in Westbury, at 1900 BST on Thursday.
Wiltshire Council is reviewing leisure services in the country although nowhere has been earmarked for closure as yet.
But those who use the Intex inflatable family size swimming pool fear it could be a target and have already started a campaign to save it.
Bob Lee, one of the main organisers of Save Westbury Inflatable Swimming Pool, said: “We recently lost our community hospital which was perfectly good, the building wasn’t falling down.
“It was a fantastic place and we maybe started a little late on that. We’re not going to get caught out this time.”
Pam Cox, who regularly uses the pool to ease pain in her joints, said: “It would have a major impact on my life.
A consultation is under way and there will be no announcement until the summer.
Councillor Stuart Wheeler, who is leading the review, has said the popularity of the pool and its history would be taken into account.

An hour long hailstorm from space may have changed the climate of the Earth

A comet may well have caused the earth to freeze for over 1,000 years.

A new theory put forward by according to Professor Bill Napier, from the Cardiff  University Astrobiology Centre suggests it occurred when the Earth strayed into a dense trail of fragments shed by a large comet.

Thousands of chunks of material from the comet would have rained down on Earth, each one releasing the energy of a one megaton nuclear bomb.

The catastrophe, caused by a disintegrating comet, wiped out large numbers of animal species and disrupted human cultures.

The impacts would have triggered wildfires covering whole continents, filling the atmosphere with smoke and soot and blotting out the Sun.

What caused a sudden cooling of up to 8C just as the Earth was warming at the end of the last ice age has puzzled scientists.

The change caused glaciers to re-advance and coincided with the rapid extinction of 35 families of North American mammals.

Evidence exists of an extraterrestrial event, such as an asteroid or comet impact.

Experts have found a ”black mat” of soot a few centimetres thick thought to be left by continental-scale wildfires.

Microscopic ”nanodiamonds” produced by massive shocks and only found in meteorites or impact craters have also been discovered dating back to the disaster.

These findings led to suggestions that an object from space four kilometres across smashed into the Laurentide ice sheet, which at the time covered what is now Canada and the northern US.

But the likelihood of the Earth being struck by such a large object only 13,000 years ago are a thousand to one against.

Also, a single impact cannot explain the occurrence of such widespread fires.

The fragmenting comet theory is more plausible, according to Professor Bill Napier, from the Cardiff  University Astrobiology Centre.

He believes there is ”compelling evidence” to indicate that such a comet entered the inner solar system between 20,000 and 30,000 years ago and has been breaking apart ever since.

The destruction of the comet has given rise to a number of closely related meteor streams known as the Taurid Complex.

”A large comet has been disintegrating in the near-Earth environment for the past 20,000 to 30,000 years and running into thousands of fragments from this comet is a much more likely event than a single collision,” said Prof Napier.

His model, published in the journal Monthly Notices of the Royal Astronomical Society, suggests that the ”hailstorm” would have only lasted about an hour.

One recent impact that may have come from the comet is known as the Tagish Lake meteorite, said Prof Napier.

The object fell on Yukon Territory in Canada in January 2000. It contained the largest amount of nanodiamonds of any meteorite studied so far.

It would have caused thousands of impacts, generating global fires and depositing nanodiamonds at the ”extinction boundary” marking the point in time when many species died out.