Making the Decision to Buy Noise Canceling Headphones

Most people who have traveled with an MP3 player or other portable device have had the experience of intruding background noise ruining their listening experience. Noise canceling headphones can be a way of eliminating much of that interfering noise.

How do most headphones reduce noise?

Many headphones use a passive means of blocking out noise to keep it from reaching a listeners ears. Both the padding on around-the-ear headphones and the ear canal blocking aspect of earbud style earphones can reduce the amount of intrusion. Blocking noise passively is the primary means of reducing higher pitch sounds and very loud sounds such as explosions.

How do noise canceling headphones function differently?

Noise canceling headphones go a step further and actively block sound via a microphone placed near the ear to identify interfering background noise and a circuit which generates a new sound wave that cancels out the intruding sound wave from the background. This does not significantly increase the volume of sound reaching the listeners ear drum and thus does not increase the risk of damaging their hearing.

The active noise cancellation employed by noise canceling headphones works fairly well in eliminating low to mid range frequencies, but are less effective at blocking the sound of a human voice. In many instances, this is a positive attribute as it allows the wearer to hear those nearby who might need to interrupt. The intrusion of additional noise canceling sound waves generally has some effect on the overall music quality that the listener hears but at least for some of the better models the effect on sound quality is minimal.

What features will need to be considered when buying noise canceling headphones?

When choosing noise canceling headphones users need to determine which style, around-the-ear or earbud, they prefer to wear. Comfort is important and if a user is irritated with the sensation of an earbud in their ear for instance, around-the-ear or on-the-ear type headphones would be a better choice.

Like any product, the effectiveness of the various makes and models of noise canceling headphones varies significantly. Some report a 70% rate of effectiveness and others might be as high as 90%. Considering the technical specifications is important, but sometimes hearing is believing so while trying on the headphones to determine comfort, it is advisable to also compare effectiveness.

For most consumers, pricing is also a significant consideration. At the low end, some earbud headphones can come in around $20-$50, while at the high end spending around $350-$400 is also common.

For true audiophiles, those that travel in noisy environments, and those who find themselves fatigued by noisy crowded environments, noise canceling headphones can be a remedy worth considering.

Multimedia Speakers

Computer speakers, or multimedia speakers, are external speakers and are usually equipped with a male 1/8 inch stereo jack plug (usually color-coded lime green per the PC 99 standard) for computer sound cards.

However, some have an RCA connector, and some people connect the output of their computer sound cards to a conventional stereo system.

There are also USB speakers which are powered from the 5 volts at a few milliamsp provided by the USB port, per the standard. Computer speakers are usually a simplified stereo system without a radio or other media sources built in.

Computer speakers range widely in quality and in price. Typically, the computer speakers packaged with computer systems are both small and simple. There are also advanced forms of computer speakers that have graphic equalization features (bass, treble, etc.) and sometimes built-in amplifiers.

It is common to connect active/powered computer speakers to a power strip. The power outlet should, as always, preferably be grounded for safety.

Aspect Ratio Incompatibility

The television industry's changing of aspect ratios is not without difficulties, and can present a considerable problem.

Displaying a widescreen aspect (rectangular) image on a conventional aspect (square or 4:3) display can be shown:

1- in "letterbox" format, with black horizontal bars at the top and bottom

2- with part of the image being cropped, usually the extreme left and right of the image being cut off (or in "pan and scan", parts selected by an operator or a viewer)

3- with the image horizontally compressed


A conventional aspect (square or 4:3) image on a widescreen aspect (rectangular with longer horizon) display can be shown:

1- in "pillar box" format,

2- with black vertical bars to the left and right with upper and lower portions of the image cut off (or in "tilt and scan", parts selected by an operator)

3- with the image horizontally distorted


A common compromise is to shoot or create material at an aspect ratio of 14:9, and to lose some image at each side for 4:3 presentation, and some image at top and bottom for 16:9 presentation. In recent years, the cinematographic process known as Super 35 (championed by James Cameron) has been used to film a number of major movies such as Titanic, Legally Blonde, Austin Powers, and Crouching Tiger, Hidden Dragon.

This process results in a camera-negative which can then be used to create both wide-screen theatrical prints, and standard "full screen" releases for television/VHS/DVD which avoid the need for either "letterboxing" or the severe loss of information caused by conventional "pan-and-scan" cropping.

Television

Television is a telecommunication system for broadcasting and receiving moving pictures and sound over a distance. The term has come to refer to all the aspects of television from the television set to the programming and transmission. The word is derived from mixed Latin and Greek roots, meaning "far sight": Greek "tele", far, and Latin visio-n, sight (from video, vis- to see).