Is there a dominant ear? (white noise comment)

F. Frank LeFever flefever at ix.netcom.com
Sun Sep 13 21:40:59 EST 1998


See my initial post and also my followup post re more recent research
(I assume; sorry, not familiar with Tomatis).

re use of white noise: the significant aspect is not white noise vs.
phonetic/linguistic stimuli, but the importance of fine temporal
resolution, whatever the stimuli--white noise, pure tones, speech
sounds, whatever.

At an extreme, in "pure word deafness", one can demonstrate good pure
tone discrimination but severely impaired temporal resolution.

This discussion has done wonders for my memory--belatedly I recall that
I presented a word deafness case study at a meeting of the
International Neuropsychological Society a few years ago; subsequently
published somewhere.  Significant aspect was our finding it in a
traumatic head injury patient; usually reported in stroke patients.  It
was our suspicion that such cases may be more numerous than is
appreciated, but word deafness as a specific deficit is undiagnosed
because it is in the context of severe cognitive problems.  As such, it
can lead to inappropriate conclusions regarding the severity of
cognitive deficits, acute status (failing communication items of
Glasgow Coma Scale, for example), feasibility of rehabilitation
programs, etc.

re music: I believe the question of hemispheric doominance is
complicated when one compares pure tones and chords; and of course the
difference between professional musicians and musically undeveloped
subjects has been long established (much left hemisphere use in
professionals, more right hemisphere in others--I do not say amateurs,
because some amateurs are well-developed).

F. Frank LeFever, Ph.D.
New York Neuropsychology Group








In <Pine.HPP.3.95.980913090551.10656B-100000 at ccshst07> Griffith A V
Morgan <gmorgan at uoguelph.ca> writes: 
>
>Comment:
>	Yes,there is a dominant ear. This was established years ago by
>work such as that of Alfred Tomatis [Paris] on listening,the uterine
>genesis of the vestibualr/auditory system. One obvious explanation
-the
>human brain is specialized/localized for langauge functiong -areas of
the
>left lobe which not only can be shown to process language
preferentailly
>but show greater anatomical development. The left lobe receives
>neurolgical input from the right ear,jus as the right lobe areas
receive
>from the left ear. It would be useful for you to review this previous
>research before conducting further experiments. I am sslightly
surpirsed
>taht the reslts with white noise favor the right ear,since the
previous
>research is based on the assumpiton one is dealing with significat
>phonetiphonemic sound or organized soun such as music.
>Griffith Morgan
>Guelph,Ontario,Canada
>
>On Fri, 11 Sep 1998, Zoro wrote:
>
>> Hi,
>> 
>> I'm presently involved with a university group experiment. We are
>> investigating the effects of 2 point descrimination within the
visual
>> and auditory pathway and perhaps finding a link to Cortical
dominance
>> within the brain (i.e. the dominant hemisphere [left for right
handers
>> for example] will be better at the descrimination task than the
lesser
>> dominant).
>> 
>> To test each eye indvidually, we used a flicker-fusion light source
>> (flickering light bulb), varying the frequency of flicker to find
the
>> point where the source appears fused (non-blinking). The results
show no
>> 
>> difference between the eyes.
>> 
>> To test each ear individually, we used a white noise sound source,
>> hooking it to a computer to allow the incorporation of 2 no-sound
>> "blips". Separating these two breaks in the noise at varying times
>> apart, in order to find the point where they appear fused (ie. as
one
>> "blip" instead of the two "Blip blip").
>> 
>> We found that in all cases the right ear achieved a much higher
degree
>> of two-point descrimination, but have yet to come up with a
reasonable
>> conclusion as to why.
>> 
>> We are presently looking into vestibular functions/anatomy but any
help
>> would be greatly appreciated. Thanks
>> 
>> Duy (2nd year student)
>> 
>> 
>> 
>> 
>> 
>




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