Directivity of different hearing aid microphone locations.
In this study, we present a new method to derive a single-number measure of the directivity of hearing aids. The method is an extension of the conventional directivity index (DI), and is called overall directivity index (ODI). The directivities of five different hearing aid styles were compared with that of the open ear. The behind-the-ear (BTE) style showed the lowest directionality compared to the other hearing aid styles and the open ear. There were only minor differences in directivity between any of the four different hearing aid styles placed in the ear and of the open ear canal. The conventional measure of DI is less suitable for hearing aids, because it ignores sound coming from other than the frontal direction. To quantify directionality of a hearing aid in a real-life situation, we suggest the single-number ODI, weighted with the articulation index and related to a listening segment of 0-30 degrees. An application of the data is shown for a BTE with a directional microphone.
Olsen
Henrik L
HL
Unit of Technical and Clinical Audiology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden. Henrik.Olsen@cns.ki.se
Hagerman
Björn
B
D000161:Acoustic Stimulation / Q000295:instrumentation; D004867:Equipment Design; D006310:Hearing Aids; D006311:Hearing Disorders / Q000628:therapy*; D006801:Humans; D015233:Models, Statistical; D010549:Personal Satisfaction