Gain Requirements of Hearing aid Users

The relationship between hearing loss for pure tones averaged over the speech frequencies and the gain employed by experienced hearing aid users has been investigated. A median value of 0.5 was obtained for the ratio between gain and hearing loss. Closer analysis indicated a slightly lower value where the loss was of a purely sensorineural type, and a somewhat higher value where the loss was conductive in nature. An explanation for the relationship is advanced in terms of comfortable listening levels and the diminution of the dynamic range which is less for conductive lesions than for those of a sensorineural nature. Possible applications for this information are suggested in the design of hearing aid attenuators, fitting aids to children, and the use of aids with fixed gain characteristics.Sammenhæengen mellem høretabets sværhedsgrad—målt som gennemsnitstabet på talefrekvenserne—og den af patienten anvendte forstærkning er undersøgt hos træenede høreapparatbærere. Man fandt en medianværdi på 0,5 for forholdet mellem forstærkning og hørenedsættelse, således at den benyttede forstærkning steg med 1 dB, når hørenedsæettelsen tiltog med 2 dB. En nærmere analyse viste, at værdien var lidt lavere hos patienter med perceptive høretab, lidt højere ved konduktive lidelser. Det afgørende er utvivlsomt dynamikomraddets bredde. Resultaterne har formentlig betydning for udformningen af volumenkontrollen på høreapparater, for høreapparatbehandlingen af børn samt for brugen af høreapparater med fast volumenkontrolindstilling.