| 摘要 |
<p>PURPOSE:To improve an S/N by arranging microphones in such a way that the widest interval between adjacent planes is a half or nearly a half the wavelength of a sound of the upper limit frequency of the frequency band of an input object. CONSTITUTION:Two microphones 1, 2 are arranged at an interval of (d) and the interval (d) is selected to a half the wavelength of the sound having the upper limit frequency of the frequency band of an input object. Then the microphones 1, 2 are arranged at a interval of d=lambda4k/2, where lambda4k is the wavelength of the sound at the limit frequency and the frequency band is 0-4kHz. When the interval (d) of the microphones is selected to be lambda4k/2 in this way, that is, the interval is a half the wavelength of the sound at the band upper limit frequency, the S/N improvement PF is best. Thus, the spatial areasing being the most effective factor of the improvement quantity of the S/N is prevented from being generated and the S/N improving quantity at a low frequency is best improved.</p> |
