| Abstract: | Random polarity-modulated sequences were produced with a uniform short-term spectrum over defined sampling intervals by a method described by Pierce, Lipes, and Cheetham J. Acoust. Soc. Am. 61, 1609-1621 (1977)]. These are identified as PLC sequences. By contrast, unconstrained random polarity-modulated pulse trains with a constant interpulse interval may depart from a short-term uniform spectrum. It is shown that listeners can clearly discriminate between PLC sequences and unconstrained random sequences, and can discriminate among different PLC sequences. This discrimination is more nearly related to the statistical redundancy of the PLC sequences. This discrimination is more nearly related to the statistical redundancy of the PLC sequences than to their run-length distribution. Such discrimination is relatively resistant to moderate degrees of temporal jitter and is obtained with other forms of information coding. Discrimination of PLC sequences is presumably based upon phase information. |
