Spectral balance as a cue in the perception of linguistic stress.

In this study, the claim that intensity, as an acoustic operationalization of loudness, is a weak cue in the perception of linguistic stress is reconsidered. This claim is based on perception experiments in which loudness was varied in a naive way: All parts of the spectrum were amplified uniformly, i.e., loudness was implemented as intensity or gain. In an earlier study it was found that if a speaker produces stressed syllables in natural speech, higher frequencies increase more than lower frequencies. Varying loudness in this way would therefore be more realistic, and should bring its true cue value to the surface. Results of a perception experiment bear out that realistic intensity level manipulations (i.e., concentrated in the higher frequency bands) provide stronger stress cues than uniformly distributed intensity differences, and are close in strength to duration differences.