We audiologically assessed newborn and infant hearing loss in 45 babies and infants from April 2003 to April 2004. To examine ABR and MASTER, the coefficient of correlation for 4kHz was 0.876, and 0.891 for 2kHz. The MASTER result (mean±SD) in passes in AABR is 0.5kHz: 39±7HL, 1kHz: 30±9HL, 2kHz: 32.5±10HL, and 4kHz: 31.2±10HL. The MASTER result (mean±SD) of passes in DPOAE was 0.5kHz: 39±12HL, 1kHz: 32±12HL, 2kHz: 29±10HL, and 4kHz: 33±9HL. For ABR, it (mean±SD) was 33±9nHL. From our data, MASTER has the advantage of frequency peculiarity and inspection time is short by simultaneous measurement in the left and right ear. We also examined MASTER under natural sleep after AABR.
Behavioral audiometry and careful examination with ABR were done on 74 new-born babies screened by AABR and/or OAE for 5 years beginning from September 1999 and progress has been observed. Reduced hearing ability was detected in 7 children. The reduction of hearing ability was confirmed by plotting the results of hearing examinations of children on a standard curve of hearing development. The reduction of hearing ability most frequently occurred around the age of 1 year and 6 months. These results suggest that it is desirable to conduct hearing examinations during the health care examination at the age of 1 year and 6 months for early detection of hearing impairment of infants. The reduction of hearing was most likely to occur in those children with high risk of hearing impairment, i. e., familial hearing impairment, babies born with asphyxia, and babies with low birth weight. The ultimate purpose of neonatal hearing screening is to implement appropriate diagnosis and begin therapeutic childcare without imposing excessive burden on children and families.
We defined cases of sudden deafness with progressive hearing deterioration after the initial visit as slow sudden deafness. We studied clinical characteristics in 34 cases compared to 38 cases of Meniere disease (MD) and 15 cases of perilymphatic fistula (PF). In the typical course in the contour of audiograms of slow cases, saucer-shaped audiograms and high-tone loss were shown at the initial visit, and flat audiograms were shown after hearing deterioration, then hearing recovered to the initial audiogram contour. In most slow cases, hearing deterioration finished within 10 days and hearing recovery occurred within month after the initial visit, these after becoming stable. In contrast, many cases of MD and PF showed progressive hearing loss after 10 days and fluctuating levels for several months or years.
Usher's syndrome is an autosomal recessive disorder characterized by retinitis pigmentosa, sensorineural hearing loss, and variable vestibular deficit, with 3 major phenotype classes, —type I, II, and III. We report 6 patients with Usher's syndrome types II and type III treated between January 2001 and August 2003. One with Usher type II showed vertigo and others showed right-and-left difference in hearing ability. The big difference when symptoms were developed was observed in 2 examples with Usher type III. The degree of symptom and time of appearance may thus vary in the same type of Usher's syndrome.
Sudden deafness is known to be a disease that typically does not relapse. Consequently, although some relapsed cases have benn previously reported, they are very few. We present a report on 2 rare cases of relapsed sudden deafness. Case 1: A 53-year-old woman with successfully treated sudden deafness showed acute perceptive deafness localized in the same ear 4 months after therapy. Case 2: A 38-year-old man with cured sudden deafness showed, similarly to case 1, acute perceptive deafness localized in the same ear 2 weeks after therapy. Interestingly, whereas therapy for relapsed deafness in case 1 was successful, it was not effective in relapse in case 2. In both cases, audiograms showed identical symptoms of incipient and relapsed disease. The cause of different progression and therapeutic response in relapsed disease in these cases remains unclear.
We analyzed the vowel confusion in 3 groups of sensorineural deafness. Each group was tested with 1 of 3 different monosyllabic lists, i. e., 57S (57), TY 89, and 67S. The frequency (%) of confusion and its details, including no response, were calculated in each 9 steps of a discrimination score across 98 to 2%, which provided a good overview of the confusion pattern in a group of sensorineural deafness. Based on the confusion pattern, the frequency of confusion of isolated vowels is distinctly higher than that of vowels in cv syllables and almost comparable to that of consonants. The confusion patterns of the 3 sensorineural groups were much alike and the majority of confusion of isolated vowels were of the V→ACV form, indicating the need for research on the mechanism behind this phenomenon.
We studied a hearing self-assessment by a patient with a cochlear implantation. The subject was a hearing-impaired child who had received a cochlear implantation at the age of 7 years. A hearing self-assessment was performed 2 months before and 2, 6, 12, and 18 months after the implantation using a set of 28 items that we developed. The results were as follows. 1) The subject was conscious of a change in his hearing after the coclear implantation. 2) The subject was able to precisely judge the improvement in his hearing based on the change in the aided threshold after the implantation. 3) The subject could distinguish among 5 vowels at 6 months after the implantation. The subject could understand the speech of intimate teachers and friends at 18 months after the implantation but could not understand speech over the telephone or on television. 4) Clearly, even a 7-year-old child was capable of performing a hearing self-assessment.