Abstract: The present invention provides a signal processing device that allows a user, who adjusts a signal level to match a reference level, to adjust the signal level while checking a degree of difference between the signal level and the reference level. A signal processing device according to the present invention comprises: an input part 20 to which an input signal is input; a storage 40 that stores therein one or more setting values of a parameter to be used for amplifying the input signal and a reference value of the setting value; an amplification part 30 that generates an output signal by amplifying a level of the input signal based on the setting value; an output part 70 that outputs the output signal; an adjustment part 50 that adjusts the setting value; and a display 60 that displays a display result determined based on the setting value adjusted by the adjustment part and the reference value.

Abstract: A method for determining microphone position is a method for determining positions of a plurality of microphones in a microphone array having the plurality of microphones arranged in a plurality of concentric circles. The method for determining microphone position includes a constraint condition acquiring step of acquiring constraint conditions including the maximum number of the plurality of microphones; and a selecting step of selecting, from among a plurality of combinations of (i) the number of microphones included in each of the plurality of concentric circles and (ii) the radius of each of the plurality of concentric circles, a combination indicating directional characteristics with the smallest difference from a target value of the directional characteristics of the microphone array; where the plurality of combinations satisfy the constraint conditions.

Abstract: A microphone includes an outer wall member having a sound hole, a first mesh arranged inside the outer wall member and made of Dutch weave, and a spacer having a diameter corresponding to an inner diameter of the outer wall member. The first mesh is pressed to an inside the outer wall member while a first surface of which is in contact with the first mesh. A second mesh is in contact with a second surface of the spacer and has water repellency. A microphone unit is stored under the second mesh.