Re: ear canal length

[Tony Miller <ajmiller@xxxxxxx>]

David Schwartz wrote:
> Can anyone direct me to published data on age-related differences in
> human ear canal length? My intuition is that ear canal length scales
> with overall head size and thus that infants have shorter canal length
> than adults, but I'd like to see the actual numbers. Any help greatly
> appreciated.
Hi David-

Maybe some of the data from this study would be useful?

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The resonance frequency of the external auditory canal in children.

Dempster JH, Mackenzie K.
Department of Otolaryngology, Royal Infirmary, Glasgow, United Kingdom.
Ear and Hearing, 1990 Aug;11(4):296-8.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2210104&dopt=Abstract

The frequency of the resonance peak of the external auditory canal was
measured in 250 children aged 3 to 12 years. The mean resonance peak
frequency was greatest in the younger age groups (3089 Hz in 4 year
olds, range 2298 to 3763) and then decreased with age until 7, the age
at which adult values were reached. Children less than 7 years of age
have mean resonance frequencies significantly different from adults,
suggesting that the "adult" length of external auditory canal is not
reached until the age of 7. This alteration in resonance frequency with
age may have practical implications by affecting the insertion gain of
hearing aid systems in children.
----------------------------

Best,
Tony

--
Tony Miller
Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary
243 Charles St, Boston, MA 02114
ajmiller@mit.edu | (617) 510-3629 | http://tonymiller.info