1. A method for automatic speech recognition, the method comprising: determining for an input signal a plurality of scores representative of certainties that the input signal is associated with corresponding states of a speech recognition model; using the speech recognition model and the determined scores to compute an average signal; computing, via a processor device executing instructions, a difference value representative of a difference between the input signal and the average signal; and processing, via the processor device, the input signal in accordance with the difference value; wherein computing the average signal comprises: identifying a given score from the plurality of scores; selecting from the plurality of scores a set of scores whose corresponding values are within a predetermined threshold from a value of the given score; and performing an averaging operation on observation mean vectors of observation densities associated with the selected plurality of scores to obtain the average signal.
1. A method for automatic speech recognition, the method comprising: determining for an input signal a plurality of scores representative of certainties that the input signal is associated with corresponding states of a speech recognition model; using the speech recognition model and the determined scores to compute an average signal; computing, via a processor device executing instructions, a difference value representative of a difference between the input signal and the average signal; and processing, via the processor device, the input signal in accordance with the difference value; wherein computing the average signal comprises: identifying a given score from the plurality of scores; selecting from the plurality of scores a set of scores whose corresponding values are within a predetermined threshold from a value of the given score; and performing an averaging operation on observation mean vectors of observation densities associated with the selected plurality of scores to obtain the average signal. 14. The method as in claim 1 further comprising: segmenting the input signal into frames; computing a respective coefficient for each of the frames; normalizing the coefficients associated with the frames; presenting the normalized coefficients to a speech recognition decoder; and computing the plurality of scores using the normalized coefficients.