The self-recording audiometry by Bekesy is described in this paper. Two kinds of tracings can be obtained in this audiometry, conventional and fixed-frequency tracing. In the conventional tracing, the frequency is gradually moved upward from 125 to 8000Hz. In the fixed-frequency tracing, the frequency is preset and tracings are obtained over a three-minute period. In either case, a complete test always consists of two separate tracings obtained with interrupted and continuous-tone stimuli. In this test, the width of the continuous tracing, the difference in width between tracing at high and low frequency, the difference in level between continuous and interrupted tracings, etc., are evaluated, and the results may be categorized into five types of abnormalities (Jerger classification). Normal or lesions of the middle ear are characterized by a type I abnormality, lesions of the cochlea by type II, lesions of the eight nerve (retro-cochlear) by type III or IV, and functional hearing loss by type V. The self-recording audiometry is especially useful for the differential diagnosis of hearing loss.
Objective audiometry is important to the hearing evaluation and the fitting of hearing aid in infants. However, the improvement, the deterioration and the fluctuation are occasionally experienced among examinations in a long-time. We investigated the threshold change of ABR and ASSR in infant audiometry. Subjects were 78 children, who were examined with ABR or ASSR to predict their hearing level two times or more. We got results the number of improvement, deterioration and fluctuating, were 12 cases (15.3%), 2 cases (2.5%), and 2 cases (2.5%), respectively. Especially, 8 of 18 cases who were examined for the first time till six months old, showed improvement of threshold. Recently, the examinees's age are going to become lower since the beginning of the hearing screening for new born baby. Plural hearing evaluation and a long time follow-up are important for infants.
One hundred eighty-five cases with functional hearing loss (39 males, 146 females) were investigated. The final audiogram obtained and the subjective awareness of hearing loss were examined. Follow-up of all the cases was intended until their audiogram became normal, or if this was not achieved in the near-term, for at least a year. According to the age at diagnosis, the cases were classified into 3 age groups; there were 130 cases in the under 11 years old group, 40 cases in the 12 to 17 years old age group, and 15 cases in the 18 years old or over age group. A normal audiogram at the final examination was obtained in 81.5% of the cases in the under 11 years old age group, 60% of the cases in the 12 and 17 years old age group and 47% in the 18 years old or more age group. Eighty-six percent of the cases in the under 11 years old age group were no longer conscious of their own hearing loss at the time of the final examination. On the other hand, a lower percentage, that is, 60% of the cases between 12 and 17 years old and 47% of the cases 18 years old or over were not aware of their hearing loss at the time of the final examination. About 20% of all the cases under 17 years old showed a discrepancy between the abnormalities in the final audiogram and the subjective awareness of hearing loss. Awareness of hearing loss is as important as audiometry test abnormality in the assessment of the seriousness of the functional hearing loss in the younger age group. The audiogram abnormality was well correlated with subjective hearing disturbance in the adults. Pure-tone audiometry is a good test to estimate the severity of functional hearing loss in adults.
The differences between hearing aids with and without noise reduction in relation to the purchasing ratio, frequency response and compression ratio of hearing aids were examined in 148 patients with hearing loss. The patients ranged in age from 20 to 89 years old. The results were as follows. 1) Patients in their fifties showed the highest purchase ratio of hearing aids with noise reduction. 2) In relation to the frequency response, the output sound pressure level at low frequency ranges below 2000Hz was higher in the hearing aids with noise reduction than in those without noise reduction. 3) The compression ratio of hearing aids at high frequency ranges above 1000Hz were higher in the hearing aids with noise reduction than in those without noise reduction. These results may be useful for hearing-aid-fitting of digital hearing aids with noise reduction.
A questionnaire survey of 102 individuals with profound hearing loss was conducted to investigate their daily use of hearing aids and to obtain information about the audibility of speech and sounds in the everyday environments from these individuals. All respondents had worn hearing aids from an early age. The hearing level was greater than 90 dB in all the subjects. Thirty-five different listening situations were described and the respondents were asked to rate whether they “could hear the sound” or “could not hear the sound but needed to hear it.” Analysis of the responses seemed to indicate that these respondents with profound hearing loss mainly judged their hearing from the sound intensity and also judged their necessity from the social context. The reasons why they wore their hearing aids almost all day long were investigated by checking their response patterns to the questions on environmental sounds, music and song, speech communication to friends and family members, and speech information. The results showed that these respondents enjoyed speech communication with their hearing friends and family, however they reported having some difficulty in understanding speech information. The respondents also reported that they enjoyed listening to music and singing in their daily lives, however, that they didn't appreciate feeling and healing sounds. The survey results also suggest that the subjects wore hearing aids on a daily basis primarily for the avoidance of danger.
CHARGE association is a multiple congenital malformation syndrome with distinctive consensus diagnostic criteria, characterized by ocular coloboma, heart disease, choanal atresia, cranial nerve defects, distinctive external and inner ear abnormalities, hearing loss, cardiovascular malformations, genital hypoplasia, and retarded growth and/or development. The purpose of this study was to investigate in the defects in? hearing and progress of using with the use hearing aids in five children with CHARGE association. Three cases were diagnosed to have bilateral sensorinural hearing loss (SNHL). They had auricularauricular malformations, but no inner ear malformations. We fitted hearing aids and supported the developmentdevelopment of communication skills in them. One of three cases had severe SNHL, one had moderate to severe SNHL, and one had mild to moderate SNHL. Because all of them had respiratoryrespiratory and feeding problems, there was difficulty in the fixing the hearing aids (HA) when they were infants. But two of three were able to wearing HA and had the effects of HA occasionally getting better physical condition However, the hearing aid could be fixed in two of the three patients, in whom the benefits of its use were noted in terms of a better physical condition??.. The condition of the remaining patient also improved when the hearing aid was fixed after the respiratory status improved??.. To support the development of communication skills, it was necessary to follow up the patients over the long term to ensure that they remained in good physical condition and facilitate their skills at communication and hearing compensations.
We evaluated 50 infants who were referred to our center for advanced hearing tests after neonatal hearing screening between April 2005 and March 2006. Conditioned orientation reflex (COR), distortion product otoacoustic emission (DPOAE), auditory brain stem response (ABR) and auditory steady-state response (ASSR) were used for precise diagnosis. The results were as follows: 22 infants had bilateral hearing impairment, 19 infants had unilateral hearing impairment, and 9 infants had normal hearing. The average age at the start of use of a hearing aid was 6 months in the infants with severe hearing loss, 8.2 months in infants with moderate hearing loss, and 8 months in children with mild hearing loss. Eary identification of hearing impairment is important for language development. In this investigation, a prompt diagnosis could be made in infants with severe hearing loss, who were then immediately prescribed appropriate hearing aids. On the other hand, detection of mild or moderate hearing impairment was difficult and sometimes the hearing thresholds changed, with time. Thus, attention must be paid to all infants detected to have problem hearing during neonatal hearing screening, as these infants may need to be followed up for a long period of time.
We investigated the actual status of Newborn Hearing Screening (NHS) in Yamagata prefecture by conducting a questionnaire survey of 66 obstetricians in the region. NHS was performed at 14 maternity clinics: using automated auditory brainstem response (AABR) at 6 clinics and otoacoustic emission (OAE) at 8 clinics. About 33% of the neonates in Yamagata prefecture were screened. At the Yamagata University Hospital, behavioral audiometry and careful examination by evaluation of the auditory steady-state response (ASSR) as well as conventional ABR were performed in 32 infants referred after NHS. Among the 19 infants referred following screening by AABR, binaural hearing loss was detected in 3. Among the 13 infants referred after screening by OAE, none was detected to have hearing loss. Thus, as compared with OAE, AABR appears to have greater sensitivity and, therefore, to be more suitable for NHS.