Binaural hearing spectacles with "no mould" by acoustic trauma

Patients with selective hearing loss in the trebles, as commonly seen in acoustic trauma, often have a considerable hearing handicap. They seldom benefit from the usual hearing aids with closed ear moulds. When Ewertsen (1970) and Cortois (1972) reported their experiences with binaural fitting of hearing spectacles, using a free plastic tube in the ear canal ("no mould"), we at the Hearing Centre in Namsos began to fit such hearing aids to 33 patients with acoustic traumas. All of them were followed-up in February--March 1978. The results have been evaluated on the basis of answers from the patients entered on questionnaires, and speech audiometry in open field, monosyllable, with 60 dB wide-band background noise. 27 patients (80%) stated that they were greatly satisfied, and 7 (20%) well satisfied. The average daily use was 4 1/2 hrs. All of the patients emphasized the great benefit obtained with the hearing aid at conferences, meetings, social occasions, etc. The average hearing gain was 13 dB. Among those who had discrimination loss there was an average gain of 30% .