bigaudioblowhard wrote on Mon, 28 February 2005 19:57 |
Dont forget our hearing probably evolved for other purposes than relative eq and levels within music. i appreciate the honesty of the member who hears something and posts in.
|
Well, it evolved to hear and localize dangers, which requires some symmetry to left and right. Language, music, one hand clapping etc., were secondary...
However, there is evidence that even if your two ears _are_ the same, they are wired to get speech in the right and music in the left!
From the auditory list
--
"Asymmetric Cochlear Processing Mimics Hemispheric Specialization"
Described in Science, Vol 305, Issue 5690, 1581 , 10 September 2004
by Y. S. Sininger and B. Cone-Wesson:
"We always assumed that our left and right ears worked exactly the same way," said lead researcher Yvonne Sininger of the University of California at Los Angeles. "As a result, we tended to think it didn't matter which ear was impaired in a person. Now we see that it may have profound implications for the individual's speech and language development."
The discovery, described in the current issue of Science Magazine, will help doctors enhance speech and language development in hearing-impaired newborns and the rehabilitation of persons with hearing loss.
Sininger and her colleagues studied hearing in more than 3 000
newborns, specifically tiny amplifiers located in the outer hair cells of the inner ear.
These cells contract and expand to amplify sound vibrations, convert the vibrations to neural cells and send them to the brain.
The scientists inserted tiny probes into the babies' ears that emitted two different types of sounds and measured the amplified vibrations. They found that speech-like clicks triggered greater amplification in the right ear, while music-like sustained tones were more greatly amplified by the left ear.
"We were intrigued to discover that the clicks triggered more
amplification in the baby's right ear, while the tones induced more amplification in the baby's left ear," Sininger said. "This parallels how the brain processes speech and music, except the sides are reversed due to the brain's cross connections."
"Our findings demonstrate that auditory processing starts in the ear before it is ever seen in the brain," said co-author Barbara
Cone-Wesson of the University of Arizona. "Even at birth, the ear is structured to distinguish between different types of sound and to send it to the right place in the brain."
--
DC