Band Width and Channel Capacity Necessary to Transmit the Formant Information of Speech
James L. Flanagan · The Journal of the Acoustical Society of America · 1956
Computations of the band widths and signal-to-noise ratios necessary for the transmission of continuous data on the first three formants of speech are presented. The results indicate that, on the average, band widths of 7.1, 6.7, and 5.3 cps and signal-to-noise ratios of 33, 24, and 20 db are sufficient for the transmission of signals specifying the frequencies of the first, second, and third formants, respectively. The band-width and signal-to-noise figures are computed on the basis that the error incurred in each formant signal is less than the just discriminable difference in formant frequency at least 65% of the time. The channel capacity necessary for the transmission of the three formant signals is, therefore, of the order of 200 bits per second.