4.2 Selecting the layout of the microphone array

Problem

Read this section when mounting microphones on your robot.

Solution

The precondition for layout is that the relative positions between individual microphones do not vary. The appropriate layout for accuracy of localization and separation depends on the directions of sound sources. If a sound source is located in a specific, known direction, the microphones can be positioned close to that direction. It is better to place microphones at wide intervals and perpendicular to the normal vector of the specific direction. If sound sources are located in all directions, then the microphones should be positioned in a circular pattern. Since wider inter-microphone intervals are better for sound source separation, the microphones should be dispersed as far apart as possible. A layout of microphones poor in sound source localization can result in poorer sound source separation. Therefore, the layout should be dependent on sound source localization. If localization accuracy is not good, reconfigure the layout so that it is not in a shape in which acoustic reflection becomes discontinuous around microphone positions, and avoid such locations for positioning.

Discussion

When the relative position between microphones varies, so will the impulse response of a microphone array. We presume here that the impulse responses of a microphone array are fixed in HARK.