26. The method of claim 19 , wherein the at least one first audio feature and the at least one second audio feature are based on at least one statistical parameter of the frequency spectrum of the at least two adjacent to-be-transcribed speech audio segments; and wherein the at least one first audio feature differs from the at least one second audio feature when at least one first value of the at least one statistical parameter of the frequency spectrum of the at least one first to-be-transcribed speech audio segment or at least one second value of the at least one statistical parameter of the frequency spectrum of the at least one second to-be-transcribed speech audio segment exceeds a pre-determined tolerance level.
26. The method of claim 19 , wherein the at least one first audio feature and the at least one second audio feature are based on at least one statistical parameter of the frequency spectrum of the at least two adjacent to-be-transcribed speech audio segments; and wherein the at least one first audio feature differs from the at least one second audio feature when at least one first value of the at least one statistical parameter of the frequency spectrum of the at least one first to-be-transcribed speech audio segment or at least one second value of the at least one statistical parameter of the frequency spectrum of the at least one second to-be-transcribed speech audio segment exceeds a pre-determined tolerance level. 27. The method of claim 26 , wherein the determination of the at least one statistical parameter of the frequency spectrum is based on statistical clustering; and wherein the at least one statistical parameter is selected from the group consisting of: mean frequency, standard deviation, median, first quartile, third quartile, interquartile range, skewness, kurtosis, spectral entropy, spectral centroid, spectral spread, spectral flux, spectral rolloff, spectral flatness, mode, peak frequency, average and minimum (min) and maximum (max) fundamental frequency, average and min and max dominant frequency, range of dominant frequency, modulation index, zero crossing rate, energy, entropy of energy, Mel frequency cepstral coefficients (MFCCs), chroma vector, and chroma deviation.