The patients with sensorineural hearing loss depend greatly on the use of hearing aid for communication, because no effective treatment of perceptive deafness has been established. They usually expect much advantages by using the instruments. Therefore otologists and audiologists should request for makers to improve the hearing aid and select a suitable hearing aid for each patient. It is also necessary to do auditory training and guidance including the better use and limitations of the hearing aids.
This study was performed in order to inquire the effects and the limits of hearing aid using the Master Auditory Trainer. The power and response of the modurated sound with this trainer was variable voluntarily. The hearing abilities of patients were measured by different test of speech using this trainer.
The receptive articulation score of the hearing impared were increaced when they could recognize the sounds of 70-80 dB (audiometer level) filtered at 1000-2000 Hz. However, voice sounds amplified to 90 dB or more (audiometer level) did not improve significantly the score.These phenomenas related to the auditory sensation area of patients, especially to the uncomfortable hearing level.
For example, in the narrow hearing area or the lower uncomfortable level, their articulation score were not improve with any amplifeid speech sound regardless their hearing loss or hearing curve.
Though it is impossible to determine the frequency characteristics of the hearing aid from hearing curve in the audiogram, a favorable frequency caracteristics for the deaf can be presumed to by the average level of hearing loss. It is hoped that the prescription of the hearing aid be made. The above-mentioned facts should be taken into consideration in auditory training for the patient.