Speech rate determination by vowel detection on the modulated energy envelope

In this paper we propose a new algorithm to detect vowels in a speech utterance and infer the rate at which speech was produced. To achieve this we determine a smooth trajectory that corresponds to a high frequency energy envelope, modulated by the low frequency energy content. Peak picking performed on this trajectory gives an estimate of the number of vowels in the utterance. To dispose of falsely detected vowels, a peak pruning post-processing step is incorporated. Experimental results show that the proposed algorithm is more accurate than the two speech rate determination algorithms on which it was inspired.