Sound zoom method, medium, and apparatus

Abstract

A sound zoom method, medium, and apparatus generating a signal in which a target sound is removed from sound signals input to a microphone array by adjusting a null width that restricts a directivity sensitivity of the microphone array, and extracting a signal corresponding to the target sound from the sound signals by using the generated signal. Thus, a sound located at a predetermined position away from the microphone array can be selectively obtained so that a target sound is efficiently obtained.

1 . A sound zoom apparatus comprising:
 a null width adjustment unit generating a signal in which a target sound is removed from sound signals input to a microphone array by adjusting a null width that restricts a directivity sensitivity of the microphone array; and   a signal extraction unit extracting a signal corresponding to the target sound from the sound signals by using the generated signal.   
     
     
         2 . The apparatus of  claim 1 , wherein the null width adjustment unit adjusts a predetermined factor of the microphone array according to a zoom control signal so that the null width is adjusted so as to correspond to the adjusted predetermined factor. 
     
     
         3 . The apparatus of  claim 1 , wherein the null width adjustment unit comprises:
 a delay of a first sound signal of the sound signals, which is delayed by a value corresponding to a zoom control signal;   a subtractor subtracting a second sound signal of the sound signals from the first sound signal that is delayed; and   a low pass filter generating a signal in which the target sound is removed, by allowing a result of the subtraction to be low-pass filtered.   
     
     
         4 . The apparatus of  claim 1 , wherein the signal extraction unit comprises:
 a noise filter estimating the generated signal as noise; and   a subtractor subtracting a signal estimated as the noise from the sound signals, and the noise filter feeds back sound signals from which the signal estimated as the noise is subtracted.   
     
     
         5 . The apparatus of  claim 1 , further comprising a signal synthesis unit synthesizing an output signal based on the sound signal and a signal corresponding to the target sound according to a zoom control signal to obtain the target sound. 
     
     
         6 . The apparatus of  claim 5 , wherein the signal synthesis unit linearly combines a signal corresponding to the target sound and a residual signal in which a signal corresponding to the target sound is removed from the sound signals and exclusively adjusts both of the signals which are linearly combined according to the zoom control signal.