Patent ID: 6600824
Filing Date: 2003-07-29
Classification: H04R

Abstract:
A microphone array system comprising two microphones and a sound signal estimation processing part, which estimates a sound signal to be received in an arbitrary position on a straight line on which the two microphones are arranged,wherein the sound signal estimation processing part expresses a estimated sound signal to be received in a position on the straight line on which the two microphones are arranged by a wave equation Equation 1, assuming that a sound wave coming from a sound source to the two microphones is a plane wave, the sound signal estimation processing part estimates a coefficient b cos &thgr; of the wave equation Equation 1 that depends on a direction from which a sound wave comes, assuming that an average power of the sound wave that reaches each of the two microphones is equal to that of the other microphone, and the sound signal estimation processing part estimates a sound signal to be received in an arbitrary position on a same axis on which the microphones are arranged, based on sound signals received by the two microphones, P&it;â€ƒ&it;(xi+1,y0,tj)-P&it;â€ƒ&it;(xi,y0,tj)=a&it;{vx&it;â€ƒ&it;(xi,y0,tj+1)-vx&it;â€ƒ&it;(xi,y0,tj)}&it;&NewLine;&it;{vx&it;â€ƒ&it;(xi+1,y0,tj)-vx&it;â€ƒ&it;(xi,y0,tj)}=b&it;â€ƒ&it;cos&it;â€ƒ&it;Î¸&it;{p&it;â€ƒ&it;(xi+1,y0,tj)-p&it;â€ƒ&it;(xi+1,y0,tj-1)}Equation&it;â€ƒ&it;1where x and y are respective spatial axes, t is a time, v is a air particle velocity, p is a sound pressure, a and b are coefficients, and &thgr; is a direction of a sound source.