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1. (WO2001001731) A METHOD FOR CONTROLLING THE DIRECTIONALITY OF THE SOUND RECEIVING CHARACTERISTIC OF A HEARING AID AND A HEARING AID FOR CARRYING OUT THE METHOD

Pub. No.:    WO/2001/001731    International Application No.:    PCT/DK2000/000339
Publication Date: Fri Jan 05 00:59:59 CET 2001 International Filing Date: Sat Jun 24 01:59:59 CEST 2000
IPC: H04R 25/00
Applicants: WIDEX A/S
JENSEN, Lars, Baekgaard
Inventors: JENSEN, Lars, Baekgaard
Title: A METHOD FOR CONTROLLING THE DIRECTIONALITY OF THE SOUND RECEIVING CHARACTERISTIC OF A HEARING AID AND A HEARING AID FOR CARRYING OUT THE METHOD
Abstract:
Change over of the sound receiving characteristic of a hearing aid having spaced apart first and second microphone means (Fmic, Bmic) between the omnidirectional characteristic and a directional characteristic is effected by controlled attenuation and time or phase delay of signals derived from the signals (Xfront, Xback) from the first and second microphone means before forming and overall combined signal (Y) to be supplied to the hearing aid signal processor, whereby the overall combined signal (Y) is determined by Y = Xfront * (1 - omni * e?-jφT¿) + X¿back? * (omni - e?-jφT¿), where omni is an adjustable attenuation control parameter preferably in the range 0 ≤ omni ≤ 1 and T is a time delay corresponding to the acoustical delay between the first and second microphone means. In result, the change between the omnidirectional characteristic and any desired form of the directional characteristic is effected as a smooth change-over substantially without affecting phase relationship, time delay and amplitude characteristic of the hearing aid.