Patent ID: 6704422
Filing Date: 2004-03-09
Classification: H04R

Abstract:
A method for controlling the directionality of the sound receiving characteristic of a hearing aid having spaced apart first and second microphones, said first microphone providing a first microphone signal (Xfront) and said second microphone providing a second microphone signal (Xback), a signal processor for processing said microphone signals and an output transducer for emission of sound signals in response to output signals from the signal processor, the method comprising the steps ofselecting a control parameter omni to a value in the range from 0 to 1, selecting a time delay T, processing a signal derived from said first microphone signal by attenuation according to said parameter omni to provide a first processed signal, processing a signal derived from said second microphone signal by, attenuation according to said parameter omni to provide a second processed signal, adding said first processed signal to said second microphone signal to form a third processed signal, subjecting said third processed signal to said time delay to provide a fourth processed signal, subtracting said fourth processed signal from said second processed signal to provide a differential signal, adding said differential signal to said first microphone signal to provide an overall combined signal as determined by Y=Xfront*(1âˆ’omni*eâˆ’j&ohgr;T)+Xback*(omniâˆ’eâˆ’j&ohgr;T), â€ƒand feeding said overall combined signal to said signal processor.