Find out about headphones.
As iPods and other portable media players become increasingly popular, people are spending more time listening to music, movies and video games through headphones. These convenient accessories range in size from small, plastic earbuds to large, foam-padded cans that cover the entire ear. Headphones also vary just as widely in terms of their price and performance.
A cheap pair of earbuds cost as little as $5, while a pair of studio-quality reference headphones may cost well over $600. Despite these differences, one thing all headphones have in common is their ability to cause permanent and serious hearing loss. By knowing how to properly use headphones, listeners can avoid this pitfall and safely enjoy the clear, private sound they provide.
As sound waves travel into the ear, they are picked up by tiny hairs called stereocilia that transform them into electrical signals the brain can understand and interpret as sound. Over time, these hairs can be flattened or even worn away by loud noises, dulling the ears sensitivity to sound and causing noise-induced hearing loss (NIHL). Although some cases of NIHL may only have minor effects on the persons ability to hear and enjoy sounds, others can be relatively severe.
The good news about NIHL is that it is completely preventable, according to the National Institute on Deafness and Other Communication Disorders. To avoid causing permanent damage to their hearing, people should avoid listening to sounds over 85 decibels (dB) for prolonged periods of time. Sounds in this dangerous range include lawn mowers (90dB), motorcycles (95dB), personal music players at full volume (105dB) and rock concerts (110dB). Ear plugs and ear muffs are the best way to protect the ears against loud environmental sounds, but the only way to protect them from being damaged by headphones is to keep the sounds volume at reasonable levels.
Earbud headphones are the kind that come with most mp3 players, including iPods. They are small, light and rest just outside of the listeners ear canal. Although they are portable and cheap, earbud headphones typically do not have good sound quality. More importantly, because they do not create a tight seal against environmental noise, they may also expose listeners to noise-induced hearing loss.
To hear music in noisy environments (e.g., a bus, crowded room or train station), people wearing earbuds often increase the volume of their personal music players to drown out external sounds. Despite this tendency, earbud headphones are not inherently more dangerous than other designs, as long as they are used carefully.
Earpad headphones have round, padded earpieces that rest on top of the ears. Full-size headphones, on the other hand, have earpieces that encircle the ears completely. Depending on their construction, ergonomics and electronic components, both designs can produce sound that is clear, balanced and rich. Because they are larger than earbuds, they are somewhat less portable, although some models have earpieces that fold into the headband to make them easier to pack.
In general, full-size headphones offer better protection against environmental noise than earpad headphones, especially if they have sealed earpieces. Unlike open-back earpieces, which have metal mesh casings, sealed earpieces are enclosed with plastic, metal or wood casings that block outside sounds. They do not provide as much sound isolation as in-the-ear headphones, but sealed, full-size headphones are pretty good some models block up to 15 dB of external noise and are safer to use in noisy spots than earbuds.
Noise-cancelling headphones use a small microphone to detect external noises and cancel them out by playing sounds with opposite wave patterns in the earpieces. They can be very expensive (some cost over $300), and they do not offer much more protection against environmental sounds than sealed full-size headphones, according to HeadRoom.
Ear canal headphones, however, provide much better sound blockage, or attenuation. Many models can lower the intensity of sounds across the frequency spectrum by more than 20dB, which is relatively superb, considering that a normal conversation weighs in at about 60dB.
Because they create such a well-isolated listening environment, people using ear canal headphones can listen to music or other sounds at much lower volumes than they could with other designs. This not only protects the ears from NIHL, but it also lets them hear subtle nuances in music, dialog and special effects, making them an excellent (if not the best) choice for travelers, commuters and other people who want high-quality sound without damaging their hearing.