4. The method of claim 2 , further comprising estimating a vector of frequency spectral noise components from said first vector frequency spectral speech components and wherein (d) comprises using the vector of the estimated frequency spectral noise components for determining said first correction factor.
5. The method of claim 4 , wherein (c) comprises: squaring said frequency spectral speech components; averaging said squared frequency spectral speech components to produce a speech power mean value; averaging the estimated frequency spectral noise components to produce a noise power mean value smoothing the speech power mean value according to first and second smoothing factors to produce a first smoothed speech power mean value and a second smoothed speech power mean value; producing a first function value and a second function value from said noise power mean value; producing a first index from said first function value according to said first smoothed speech power mean value and a second index from said second function value according to said second smoothed speech power mean value; and summing said first and second indices to produce an output signal representing said speech-versus-noise relationship.