Subject: 'Speak in my right ear and sing in my left' From: hilarleo <hilarleo(at)UCLINK.BERKELEY.EDU> Date: Sat, 25 Sep 2004 08:30:14 -0700"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: http://www.sciencemag.org/cgi/content/full/305/5690/1581? maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=Sininger&author2=Cone- Wesson&searchid=1096115078660_1382&stored_search=&FIRSTINDEX=0&fdate=9/ 1/2004&tdate=9/30/2004 This finding is similar to those of enhanced processing of tones in right auditory cortical areas and of rapidly changing stimuli on the left, (given strong crossed connections from ear to brain)... Behaviorally, reaction time is faster and stimulus identification is more accurate when a subject's right ear is presented with speech-type stimuli or when the left ear is presented with tonal information ... >These findings indicate that processing at the level of the ear may facilitate lateralization of auditory function in the brain... $$$$$$$########%%%%%%&&&&& ######%%%%%%&&&&&$$$$$$$## %%&&&&&$$$$$$$########%%%% "We always assumed that our left and right ears worked exactly the same way... "We were intrigued to discover that clicks triggered more amplification in the baby's right ear..." Authorial interviews from South African Independent Media Online described as 'Speak in my right ear and sing in my left'; Full text follows. http://www.iol.co.za/index.php? set_id=1&click_id=31&art_id=qw1094984284521B226 <Washington - The right and left human ears process sound differently, according to scientists who studied the hearing of babies and found the right ear better at picking up speech-like sounds and the left more attuned to music. It has long been known that the right and left halves of the brain process sound differently, but those differences were thought to stem from cellular properties unique to each brain hemisphere. The new research suggests that the differences start at the ear. "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." - Sapa-AFP > $$$$$$$########%%%%%%&&&&& ######%%%%%%&&&&&$$$$$$$## %%&&&&&$$$$$$$########%%%% LeOSullivan. LeOSullivan 1 510 549 0146 UCBerkeley