Subjective expressions of tinnitus nature using onomatopoeias and the results of pitch match test were analyzed in 41 cases of surgically proven unilateral acoustic neuroma (AN). The pitch match test was conducted at 11 frequencies between 125Hz and 8000Hz using pure-tone audiometer following to the method of Standardized Tinnitus Test in 1984 which was proposed by Tinnitus Study Group of Japan Audiological Society.
The results obtained were as follows;
1) Sixteen kinds of onomatopoeia were used for the subjective expressions in 41 tinnitus ears.
2) When the incidence in use of each onomatopoeia was analyzed, the most frequently used onomatopoeia was “jie” (19.5%) followed by “sien”, “sah” and “pie” (9.8%). The incidence in use of “kien” was only 4.9%, which was the most frequently used onomatopoeia for the subjective expression in tinnitus ears without hearing loss or associated with cochlear deafness.
3) As far as the simulated tone of tinnitus was concerned, pure-tone was used in only 48.8%, band noise in 34.1% and white noise in 12.2%. Two tinnitus ears (4.9%) could not be simulated by either pure-tone, band noise or white noise. This result indicated that the incidence in pure-tone decreased and that in band noise and white noise increased in tinnitus ears of AN compared with that in tinnitus ears without hearing loss or associated with cochlear deafness.
4) The tinnitus pitch was distributed between 500Hz and 8000Hz and its incidence became to be higher as the frequency increased.
5) When the relationship between 16 kinds of onomatopoeia and simulated tones of tinnitus was analyzed, five onomatopoeias (31.3%) corresponded to only pure-tone (tonal onomatopoeia), five onomatopoeias (31.3%) to only band noise and white noise (noise onomatopoeia) and six onomatopoeias (37.5%) to both pure-tone and band noise or white noise (tonal-noise onomatopoeia). This result indicated that the incidence in tonal onomatopoeia decreased and that in noise onomatopoeia and tonal-noise onomatopoeia increased in tinnitus ears of AN compared with that in tinnitus ears without hearing loss or associated with cochlear deafness.
6) Based upon these results, it was concluded that the incidence in noise tinnitus is relatively high in tinnitus ears of AN which might be induced by the intricate pathophysiology of auditory dysfunction due to the coexistence of cochlear and retrocochlear impairments.
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