Articulation scores in perception of vowels uttered by normal hearing children, articulation scores in production of vowels, articulation scores in perception of vowels uttered by themselves and relations among these three scores were studied in 75 hearing impaired children. Results and conclusions were as follows. 1) Confusion of vowel perception and production showed certain tendencies. 2) Hearing impaired children with high ability of speech perception had the acoustic-phonetic boundaries nearly equal to that of normal hearing children. 3) It required ability to use auditory feedback effectively to improve clearness of speech production.
Determining correct loudness functions of a relevant hearing-impaired listener is very important for designing an appropriate characteristic for advanced hearing aid which is capable of compensating his/her distorted loudness functions. Two-step subdivision categorical scaling method is a preferable method to measure loudness functions because of its good precision and high resolution. This method, however, has some disadvantages such as complexity in procedure and experimental duration of two times as long as in the conventional categorical scaling method. Thus we propose a new method of measuring loudness functions. In this method, one stimulus is presented to a subject only once for one loudness scaling judgement and answering a scale value between categories defined is allowed. This method is called one-step subdivided categorical scaling method. Moreover, this method is very simple, its resolution is as high as the two-step subdivided categorical scaling method and the time duration needed is as short as the conventional categorical scaling method.
Since April in 1992, auditory screening at the 3-year-old children health examination has been performed in Mie prefecture. To elucidate the present status and problems of this screening, we mailed questionnaire to 69 cities, towns, and villages in February and March, 1998, and received responses from 63. Since April to December in 1997, 241 (2.18%) of 11047 children were selected for the further examinations and we investigated 162 further examination forms. 126 children visited to clinics and 35 to hospitals for further examination. Pure tone audiometry was performed only in 53 (32.7%) children. Tympanometry was examined in 231 (71.3%) ears. One case of unilateral sensorineural hearing loss was found in this auditory screening. These results suggest that the effort should be made for achievement of audiometry at the clinic and the hospitals, and children who could not be diagnosed as having normal hearing should be referred to special clinics for hearing impaired children to receive further examination. It is necessary to create comprehensive auditory screening and further examination system in the future.
The study was conducted to clarify the effects of reduction of the number of electrodes programmed, and that of changing the area in cochlear stimulated on the speech perception performance in 6 cochlear implant patients. Subjects were adult cochlear implant programming where all 22 electrodes were usable. Speech perception performance was evaluated by reducing the number of electrodes programmed from 20 to 10, to 7, to 5 as well as by changing the stimulation area and ranges with 10 channels in use. The results showed that even when the number of channels was decreased by half to 10 (every other electrode stimulated), there was no obvious decline of speech perception performance observed whereas the speech perception abilities tended to go down when the stimulation range was narrowe within the cochlea.