Method for selecting output wave beam of microphone array

A method for estimating a direction of arrival of sound signals from a microphone array, comprising the following steps:

• (a) receiving a plurality of sound signals from the microphone array comprising a plurality of microphones, and performing beamforming on the plurality of sound signals to obtain a plurality of wave beams and corresponding wave beam output signals;
• (b) performing the following operations on each wave beam in the plurality of wave beams:
• converting the wave beam output signal of a current wave beam from time domain to frequency domain to obtain a frequency spectrum vector and a power spectrum vector of the current wave beam;
• on the basis of the frequency spectrum vector and the power spectrum vector of the current wave beam, calculating an overall voice signal energy of the current wave beam, wherein the overall voice signal energy is a product of an overall energy and an overall voice existence probability of the current wave beam, wherein the overall energy indicates an energy level of the wave beam output signal of the current wave beam, the overall voice existence probability indicates an existence probability of voice in the wave beam output signal of the current wave beam, and the overall voice existence probability and the overall energy are scalar quantities;
• wherein the overall energy is obtained according to the following steps:
• averaging all elements of the power spectrum vector to obtain the overall energy;
• and the averaging comprises:
• performing weighted averaging on all elements of the power spectrum vector to obtain the overall energy, wherein for each element in the power spectrum vector, if the frequency point corresponding to the element falls in the range of 0-5 kHz, the element is given a weight of 1, otherwise it is given a weight of 0;
• (c) selecting a wave beam with a maximal overall voice signal energy value as an output wave beam;
• and
• (d) estimating the direction of arrival of sound signals from the microphone array based on a direction of the output wave beam.