Patent ID: 6137887
Filing Date: 2000-10-24
Classification: H04R

Abstract:
A sound system comprising:a first direction sensitive microphone means having front and rear microphone elements respectively coupled to front and rear output terminals, said first direction-sensitive microphone means for receiving a first acoustic signal at said front microphone element and at said rear microphone element and for producing a front electrical signal at said front output terminal representative of the first acoustic signal detected by said front microphone element and for producing a rear electrical signal at said rear output terminal representative of the first acoustic signal detected by said rear microphone element;a second direction-sensitive microphone means having front and rear microphone elements respectively coupled to front and rear output terminals, said second direction-sensitive microphone means for receiving a second acoustic signal at said front microphone elements and at said rear microphone element and for producing a front electrical signal at said front output terminal representative of the second acoustic signal detected by said front microphone element and for producing a rear electrical signal at said rear output terminal representative of the second acoustic signal detected by said rear microphone element;a first audio signal processing means coupled to said front and rear output terminals of said first direction-sensitive microphone means for producing a first microphone control signal that is active when said front electrical signal of said first direction-sensitive microphone means exceeds said rear electrical signal of said first direction-sensitive microphone means by a predetermined amount;a second audio signal processing means coupled to said front and rear output terminals of said second direction-sensitive microphone means for producing a second microphone control signal that is active when said front electrical signal of said second direction-sensitive microphone means exceeds said rear electrical signal of said second direction-sensitive microphone means by a predetermined amount;audio signal level comparison means, coupled to said first direction-sensitive microphone means to receive said front electrical signal of said first direction-sensitive microphone means and coupled to said second direction-sensitive microphone means to receive said front electrical signal of said second direction-sensitive microphone means, for determining which of said front electrical signals of said first and second direction-sensitive microphone means is greater in amplitude and for producing a max signal corresponding to the greater amplitude signal of said front electrical signal of said first direction-sensitive microphone means and said second direction-sensitive microphone means and for comparing said max signal to said front electrical signals of said first and second direction-sensitive microphone means and producing a microphone selection signal identifying which of said first and second direction-sensitive microphone means has the larger amplitude front electrical signal;a first gating means coupled to said audio signal level comparison means to receive said microphone selection signal, and coupled to said first audio signal processing means to receive said first microphone control signal, wherein an audio output signal is produced if the microphone selection signal and the first microphone control signal are both active;a second gating means coupled to said audio signal level comparison means to receive said microphone selection signal and coupled to said second audio signal processing means to receive said second microphone control signal wherein an audio output signal is produced if the microphone selection signal and the second microphone control signal are both active.