One of accepted etiologies of sudden deafness is the vascular occlusion. In this paper hearing loss due to vascular occlusions in the arteries or arterioles which supply oxygen to the inner ear are discussed. The occlusions in the anterior cerebellar artery, labyrinthine artery or common cochlear artery may cause vertigo and unreversible sensorineural hearing loss. The occlusion in the anterior vestibular artery causes only vertigo. The occlusion in the vestibulocochlear artery causes unreversible hearing loss. If blood supply returns to normal, hearing in low and middle frequencies may be able to recover. The occlusion in the external radiating arteriole at basal turn damages the stria vascularis and magnitude of endochlear DC potential would suppose to decrease in all cochlear turns. Hearing loss in all frequencies must occur. If blood supply returns to normal, hearing loss may be able to recover. The occlusion in the common cochlear artery causes unreversible hearing loss in low and middle frequencies. The occlusion in the external radiating arteriole ramified from the common cochlear artery may cause reversible low and middle frequency hearing loss. The occlusion in the internal radiating arteriole must cause unreversible dip-type hearing loss.
Meningiomas constitute approximately 13% to 18% of all intracranial tumors. Of these, approximately 8% to 12% are located in the posterior fossa. Since meningiomas are insidiously growing tumors, they are often neurologically silent until they became quite large. However, the initial symptoms are usually otologic for menintgiomas within the temporal bone, the posterior fossa, or in both. The objective of this study is to report results of electrocochleography (ECoG) in three patients with posterior fossa meningioma and to discuss the possible mechanisms of increase of -SP/AP ratio. The results of ECoG showed abnormal increase in a -SP/AP. The possible mechanisms of the increase of -SP/AP ratio are appeared to be as follows. The compression of the posterior fossa by the tumor causes dysfunctions of olivocochlear bundle and/or endolymphanic sac and/or blood flow. These dysfunctions may increase -SP/AP ratio on ECoG.
Speech discrimination performance in 26 patients with acquired moderately impaired hearing was evaluated through combined use of audimtory and visual modalities. A videotape of an announcer's face producing 25 Japanese monosyllables was used as the test material. Three test conditions were employed; 1. combined use of unamplified auditory and visual cues, 2. use of amplified auditory cues only, 3. combined use of amplified auditory and visual cues. The results were as follows; 1. combination of two modalities was generally effective for speech discrimination in patients with moderately impaired hearing, 2. patients could be classified into three types based on the test results, and there appeared to be some relationships between those types and audiometric findings, such as types of audiograms or maximum articulation scores, 3. combination or two modalities was more effective for patients with poor maximum articulation scores than for those with good scores, 4. auitory-visual discrimination tests were considered to be useful in developing the programs of the aural rehabilitation for patients with moderately impaired hearing.
Factors affecting the subjective “kiin” and “jiin” of the onomatopoeia of tinnitus were analyzed quantitatively. A total of 113 patients with unilateral tinnitus were studied. Major factors affecting the subjective “kiin” and “jiin” of onomatopoeia were age, tinnitus pitch, diagnosis, the duration of tinnitus, and pitch-matched frequency. An age of younger than 50 years was associated with the subjective “kiin” of onomatopoeia. An age of older than 60 years was associated with the subjective “jiin” of onomatopoeia. An age from 50 to 60 years was the transitional phase. High-pitch tinnitus was associated with the subjective “kiin” of onomatopoeia. Low-pitch tinnitus and ambiguous, sudden deafness, dizziness, hearing loss of elderly patients, and middle and low frequencies were associated with the subjective “jiin” of onomatopoeia. Our results suggest that the mechanism of tinnitus and construction of frequencies differ from between the “kiin” and “jiin” of onomatopoeia.
The aim of the present study is to investigate the relationship between hearing disabilities and handicaps experienced by retired workers from noisy workplace. The Japanese version of the Hearing Disability and Handicap Scale (HDHS) developed by the authors was used for self-assessment of hearing disabilities and handicaps. The questionnaire was completed by 210 workers with a compensable noise-induced hearing loss. The response rates of “Always or Sometimes” for questions regarding verbal sounds ranged from 74.3 to 91.4%, which are relatively higher than those for questions regarding non-verbal sounds which ranged from 49.2 to 70.0%. Handicap (HD) scores are closely related to averaged hearing level and also the number of years having hearing problem. Comparison of response rates for questions regarding verbal and non-verbal sounds among three groups classified by the HD-score suggested that the increase of HD-scores were connected with difficulties in enjoying TV or radio programs in the groups having lower HD-scores and with hearing difficulties in everyday conversation in those having higher HD-scores.
We analyzed answeres to questionnaires about FM hearing-aid systems, from parents and teachers. FM hearing-aid system is known to be useful, but teachers feel that it is not effective to use this system in some situations, such as out of doors. Some teachers often wonder if FM hearing-aid system is more useful for their students than conventional hearing aids. Otolaryngoloists should support teachers to use FM system effectively.