Speech prosody supports speaker selection and auditory stream segregation in a multi-talker situation.

To process speech in a multi-talker environment, listeners need to segregate the mixture of incoming speech streams and focus their attention on one of them. Potentially, speech prosody could aid the segregation of different speakers, the selection of the desired speech stream, and detecting targets within the attended stream. For testing these issues, we recorded behavioral responses and extracted event-related potentials and functional brain networks from electroencephalographic signals recorded while participants listened to two concurrent speech streams, performing a lexical detection and a recognition memory task in parallel. Prosody manipulation was applied to the attended speech stream in one group of participants and to the ignored speech stream in another group. Naturally recorded speech stimuli were either intact, synthetically F0-flattened, or prosodically suppressed by the speaker. Results show that prosody - especially the parsing cues mediated by speech rate - facilitates stream selection, while playing a smaller role in auditory stream segmentation and target detection.

Rate vs. rhythm characteristics of cluttering with data from a "syllable-timed" language.

PURPOSE: Cluttering is a type of fluency disorder characterized by a speech rate which is perceived to be fast and/or irregular as well as by an abnormal speech rhythm. As far as we know, no research has been conducted as yet using objective measurements and acoustic phonetic description on the rhythm of cluttered speech. The aim of this study is to show by objective measurements whether there are any differences between the rhythm of cluttered and control speech, and which parameters point to such differences. METHODS: For the analysis, recordings of spontaneous speech samples were taken from people who clutter (PWC) as well as from control speakers. Typical speech rhythm values and articulation rate were calculated in each speech sample. RESULTS: Results have confirmed that the rhythm of cluttering is slightly different from that of control speech in terms of various values, but the effect size is only small. It must be noted, however, that the difference between the two groups was not apparent in all analyzed values. CONCLUSION: The timing differences between cluttered and control speech are manifested primarily in the articulation rate while peculiarities in speech rhythm are almost negligible.