Speech recognition using variable frame rate coding

This paper investigates the effect of LPC based time compression schemes on dynamic programming (DP) and its alternatives. Two compression schemes, one with fixed threshold and the other with variable threshold both incorporated with two control factors, the rate of frame overlap and the step of interframe interval, are investigated. The test speech is 40-word alpha-digit vocabulary pronounced by 10 males and 10 females. Results found are: (1) limited time sequence compression does not impose any negative effect on DP or its alternatives and (2) variable threshold scheme performs better than the fixed threshold scheme. More detailed discussion on the compression schemes and DP interaction are included.