Microphone assembly and method for providing hearing assistance with optimized directivity

A microphone assembly comprising:

• at least three spaced apart microphones defining a microphone plane, each configured to capture an input audio signal from an audio source;
• an audio signal processing unit for processing the input audio signals in a manner so as to generate an output audio signal with a directivity;
• an audio source direction estimation unit including:
• a first direction of arrival estimation module for estimating a first angle of incidence between the audio source and a first axis defined by a first pair of the microphones with regard to a base point centered between the microphones of the first pair of microphones;
• a second direction of arrival estimation module for estimating a second angle of incidence between the audio source and a second axis defined by a second pair of the microphones with regard to a base point centered between the microphones of the second pair of microphones, the second pair of microphones being different from the first pair of microphones and the first axis and the second axis having different directions;
• and
• an elevation estimation module for estimating an angle of elevation of the audio source with regard to the microphone plane based on the estimated first angle of incidence and the estimated second angle of incidence;
• and
• a control unit for using the estimated angle of elevation to control a directivity parameter of the audio signal processing unit on which the directivity of the output audio signal depends,
• wherein the control unit is configured to control said directivity parameter such that the directivity of the output audio signal is reduced during times when the estimated angle of elevation is found to be above a threshold,
• wherein the audio signal processing unit includes an adaptive beamformer unit using a beamformer adaptation parameter varying between a lower limit and an upper limit,
• wherein the beamformer adaptation parameter determines a denoising performance of the beamformer unit and an attenuation of the audio source by the beamformer unit, and
• wherein the control unit is configured to adapt the lower limit and the upper limit of the beamformer adaptation parameter based on the estimated angle of elevation.