Intrinsic fO differences in spoken and sung vowels and their perception by listeners

We explore how listeners perceive distinct pieces of phonetic information that were conveyed in parallel by the fundamental frequency (fO) contour of spoken and sung vowels. In a first experiment, we measured differences in fO of /i/ and /a/ vowels spoken and sung by unselected undergraduate participants. Differences in "intrinsic fO" (with fO of /i/ higher than of /a/) were present in spoken and sung vowels; however, differences in sung words were smaller than those in spoken vowels. Four experiments tested a hypothesis that listeners would not hear the intrinsic fO differences as differences in pitch on the vowel, because they provide information, instead, for production of a closed or open vowel. The experiments provide clear evidence of "parsing" of intrinsic fO from the fO that contributes to perceived vowel pitch. However, only some conditions led to an estimate of the magnitude of parsing that closely matched the magnitude of produced intrinsic fO differences.