Sound Science: Pete Townshend Blames Headphones for Hearing Loss - Live Science

I'm interested in the measurement of the loudness of sound (decibels). This article says that it's a log scale where 20 more decibels is 100 times more intense. That would translate into a factor of 1.26 for every incremental decibel. If we play some music louder by one decibel, it would be 26% louder. Is this correct? Thanks for a confirmation.

Sailom

http://www.livescience.com/humanbiology/060104_earbuds.html

By Robert Roy Britt
LiveScience Managing Editor
posted: 04 January 200611:00 pm ET


In a widely reported story this week, rock star Pete Townshend blamed his hearing loss on earphones rather than the years of participating in loud concerts with his band, The Who.
But what is the science of his claim? Pretty solid.
Townshend has spoken of his hearing loss before but refrained from blaming headphones or speaking to the science of the situation. But having been forced to alter the style of music he writes, as well as needing to take 36-hour breaks from the noise, he felt compelled to break the silence.
"This very morning, after a night in the studio trying to crack a difficult song demo, I wake up realizing again—reminding myself, and feeling the need to remind the world—that my own particular kind of damage was caused by using earphones in the recording studio, not playing loud on stage," Townshend wrote on his web site Dec. 29.
"My ears are ringing, loudly," the guitarist wrote. "This rarely happens after a live show, unless the Who play a small club. This is a peculiar hazard of the recording studio."

The science of it

Warnings about potential hearing loss from loud concert music go back decades. Researchers in the 1980s began cautioning that the Walkman and other headphone-based music devices also packed risk.
The widespread and increasing use of headphones and the newer earbuds has been shown to induce hearing loss in young people.
An updated warning was issued just last month for the modern devices, including iPods and MP3 players.
"We're seeing the kind of hearing loss in younger people typically found in aging adults," Dean Garstecki, a Northwestern University audiologist, said in December. "Unfortunately, the earbuds preferred by music listeners are even more likely to cause hearing loss than the muff-type earphones that were associated with the older devices."
Earbuds, being inserted into rather than surrounding it, can boost sound intensity by 6 to 9 decibels, Garstecki said.

What hurts

Hearing loss is typically painless and gradual in its inception. So we don't notice it's early stages, except perhaps as a ringing in the ear known as tinnitus.
The American Hearing Research Foundation (AHRF) reports that "1-in-10 Americans has a hearing loss that affects his or her ability to understand normal speech."
The decibel (dB) scale is logarithmic, such that 40 decibels is 100 times as intense as 20 decibels. Some common sounds:

20 dB: A whisper
60 dB: Normal conversation
100 dB: Chainsaw
120 dB: Rock concert
140 dB: Jet engine
180 dB: Firecracker

Length of exposure is a crucial factor in hearing loss. A constant 100-dB sound level can cause damage after 2 hours, according to the AHRF. You don't want to experience 140 dB for even a second.

Earbud exposure

Students at Witchita State University have been found to be experiencing decibel levels of 110 to 120 during normal use of earbuds, Garstecki said.
He fears that better batteries nowadays make personal music players even more dangerous, because people can use them for long stretches. He recommends reducing the sound level and limiting use to an hour a day to stay safe.
Townshend, while not a scientist, also worries about extended use, because music is so often shared among computers in offices and kitchens, and headphones offer privacy.
"If you use an iPod or anything like it, or your child uses one, you MAY be OK," Townshend writes. "It may only be studio earphones that cause bad damage. I only have long experience of the studio side of things (though I've listened to music for pleasure on earphones for years, long before the Walkman was introduced). But my intuition tells me there is terrible trouble ahead."