8. A device configured to perform speech enhancement, comprising: a first circuit configured to obtain a speech signal using at least one input microphone; a second circuit configured to calculate a whitening filter using a silence interval in the obtained speech signal, and to apply the whitening filter to the obtained speech signal to generate a whitened speech signal in which noise components present in the obtained speech signal are whitened; and a third circuit configured to estimate a clean speech signal by applying a multi-channel filter to the generated whitened speech signal, and to output the clean speech signal to an audio device, wherein the second circuit is further configured to calculate the whitening filter by iteratively updating the whitening filter as an FIR filter sequence using NS noise samples from the obtained speech signal, NS being a positive integer, and wherein the step of iteratively updating the whitening filter comprises updating the matrix FIR filter sequence W p (k) using the iterative equation: W p ⁡ ( k + 1 ) = ( 1 + μ ) ⁢ c ⁡ ( k ) ⁢ W p ⁡ ( k ) - μ ⁢ c ⁡ ( k ) d ⁡ ( k ) ⁢ U ~ p ⁡ ( k ) , ⁢ 0 ≤ p ≤ L ⁢ ⁢ where ⁢ ⁢ d ⁢ ( k ) = 1 n ⁢ ∑ i = 1 n ⁢ ∑ j = 1 n ⁢ ∑ p = 0 L ⁢  g ijp ⁡ ( k )  , ⁢ and ⁢ ⁢ c ⁡ ( k ) = 1 d ⁡ ( k ) ( 26 ) are gradient scaling factors, i, j, k, and p are integers, μ is a real number, L is the integer length of the FIR filter, n is a number of microphones, k is an iteration index, μ is a step size, g( ) is a scaling function where g ijp are elements of a coefficient matrix G vp (k) that defines Ũ p (k), or using the iterative equation: W p ⁡ ( k + 1 ) = ( 1 + μ ) ⁢ c ⁡ ( k ) ⁢ W p ⁡ ( k ) - μ ⁢ c ⁡ ( k ) d ⁡ ( k ) ⁢ U p ⁡ ( k ) , ⁢ where ⁢ ⁢ d ⁢ ( k ) = 1 n ⁢ ∑ i = 1 n ⁢ ∑ j = 1 n ⁢ ∑ p = 0 L ⁢  g ijp ⁡ ( k )  , ⁢ and ⁢ ⁢ c ⁡ ( k ) = 1 d ⁡ ( k ) ( 20 ) are gradient scaling factors, i, j, k, and p are integers, μ is a real number, n is a number of microphones, k is an iteration index, μ is a step size, g( ) is a scaling function where g ijp are elements of a coefficient matrix G p (k) that defines U p (k).
8. A device configured to perform speech enhancement, comprising: a first circuit configured to obtain a speech signal using at least one input microphone; a second circuit configured to calculate a whitening filter using a silence interval in the obtained speech signal, and to apply the whitening filter to the obtained speech signal to generate a whitened speech signal in which noise components present in the obtained speech signal are whitened; and a third circuit configured to estimate a clean speech signal by applying a multi-channel filter to the generated whitened speech signal, and to output the clean speech signal to an audio device, wherein the second circuit is further configured to calculate the whitening filter by iteratively updating the whitening filter as an FIR filter sequence using NS noise samples from the obtained speech signal, NS being a positive integer, and wherein the step of iteratively updating the whitening filter comprises updating the matrix FIR filter sequence W p (k) using the iterative equation: W p ⁡ ( k + 1 ) = ( 1 + μ ) ⁢ c ⁡ ( k ) ⁢ W p ⁡ ( k ) - μ ⁢ c ⁡ ( k ) d ⁡ ( k ) ⁢ U ~ p ⁡ ( k ) , ⁢ 0 ≤ p ≤ L ⁢ ⁢ where ⁢ ⁢ d ⁢ ( k ) = 1 n ⁢ ∑ i = 1 n ⁢ ∑ j = 1 n ⁢ ∑ p = 0 L ⁢  g ijp ⁡ ( k )  , ⁢ and ⁢ ⁢ c ⁡ ( k ) = 1 d ⁡ ( k ) ( 26 ) are gradient scaling factors, i, j, k, and p are integers, μ is a real number, L is the integer length of the FIR filter, n is a number of microphones, k is an iteration index, μ is a step size, g( ) is a scaling function where g ijp are elements of a coefficient matrix G vp (k) that defines Ũ p (k), or using the iterative equation: W p ⁡ ( k + 1 ) = ( 1 + μ ) ⁢ c ⁡ ( k ) ⁢ W p ⁡ ( k ) - μ ⁢ c ⁡ ( k ) d ⁡ ( k ) ⁢ U p ⁡ ( k ) , ⁢ where ⁢ ⁢ d ⁢ ( k ) = 1 n ⁢ ∑ i = 1 n ⁢ ∑ j = 1 n ⁢ ∑ p = 0 L ⁢  g ijp ⁡ ( k )  , ⁢ and ⁢ ⁢ c ⁡ ( k ) = 1 d ⁡ ( k ) ( 20 ) are gradient scaling factors, i, j, k, and p are integers, μ is a real number, n is a number of microphones, k is an iteration index, μ is a step size, g( ) is a scaling function where g ijp are elements of a coefficient matrix G p (k) that defines U p (k). 9. The device of claim 8 , further comprising: a fourth circuit configured to detect the silent interval in the obtained speech signal.