[Audiological study for ears with aural stenosis and atresia].
The audiological study for ears with aural stenosis and atresia was performed. The hearing level of ears with three types of ear plugs (with the hole of phi 1mm, with the hole of phi 3mm and without the hole) was tested experimentally by 10 normal hearing subjects in pure tone audiometry, and the audiograms of congenital and acquired aural stenosis and atresia were investigated statistically. And then following results were obtained. 1) The air conduction levels were higher, as the diameter of ear plug's hole got shorter in normal hearing subjects. And the shape of their audiograms was gradual sloping type. 2) The air conduction levels of ears with congenital aural stenosis and atresia were almost from 60 to 70 dB, and the levels were almost same throughout 7 frequencies. But the audiograms of ears with acquired aural stenosis and atresia showed conductive and gradual sloping type. 3) From the results mentioned above, the reason why the hearing loss of ears with aural stenosis and atresia showed conductive hearing loss limited to low and middle frequencies was considered to depend on the abnormality of the middle ear. 4) An average value of hearing threshold level in bone conduction among normal hearing subjects with three types of ear plugs was almost -7.8dB. There was no relation between the size of ear plug's hole and the shift of bone conduction level.
Ogasawara
M
M
Kusano
H
H
Murakami
Y
Y
Higuchi
A
A
Murai
K
K
Tsuiki
T
T
D000328:Adult; D001301:Audiometry, Pure-Tone; D001844:Bone Conduction; D003251:Constriction, Pathologic / Q000503:physiopathology; D004424:Ear Canal / Q000002:abnormalities; D004427:Ear Diseases / Q000503:physiopathology; D005260:Female; D006309:Hearing; D006801:Humans; D008297:Male