Re-examining age-related differences in the perception of ‘‘say/stay.’’

Abstract

Previous ‘‘say/stay’’ perception studies using synthetic stimuli posited F1-onset frequency and gap duration as the relevant cues. Children needed shorter gaps than adults to respond ‘‘stay’’ when F1 onset weakly indicated ‘‘stay,’’ suggesting that children weight that formant transition more. Replicating these experiments with natural speech produced unexpected findings. Acoustic analysis of natural ‘‘say’’ and ‘‘stay’’ tokens showed that: (1) F1 onset did not vary for ‘‘say’’ and ‘‘stay;’’ (2) F2/F3 onsets did vary; and (3) a burst was present in ‘‘stay.’’ Perceptual stimuli, therefore, consisted of natural, burstless vocalic portions from ‘‘say’’ and ‘‘stay,’’ and these same portions with a burst added. Each portion was combined with a natural ‘‘s’’ noise at seven gap durations. The burst effect was stronger for adults than children, and F2/F3 onset had an effect only for burstless stimuli. A second experiment was designed to examine the effects of F2/F3 in burstless stimuli, but adults failed to hear any stimuli as ‘‘stay.’’ Children had no trouble. It is concluded that: (1) F1 onset is not a cue to ‘‘say/stay;’’ (2) adults have learned to use the burst as a cue to ‘‘stay’’ identity; and (3) previous results were not due to the use of synthetic speech. [Supported by NIDCD grant R01 DC 00633.]