14th International Congress of Phonetic Sciences (ICPhS-14)

San Francisco, CA, USA
August 1-7, 1999

Interrupted Tones and Repeated Syllables

William Ainsworth (1), Georg Meyer (1), Jacques Koreman (2)

(1) Keele University, UK; (2) Saarbruecken University, Germany

Two harmonically related tones are perceived as a single chord, but if one of them is periodically interrupted they are heard as two separate sound sources. If a /ma/ syllable is repeated the resulting sound consists of a continuous nasal formant with a number of periodically interrupted higher formants. Why is this utterance not perceived as two separate sound sources?
   Experiments have been performed to investigate this question. An amplitude modulated tone was added to a continuous tone. Two sources were heard if the stimulus consisted of more than one cycle of amplitude modulation. It was confirmed that repeated /ma/ syllables are perceived as a single voice whereas repeated vowels added to a continuous nasal are perceived as two voices. The signals were subjected to linear prediction analysis then synthesised at the same fundamental frequency. Perception tests showed that both of these stimuli were heard as a single voice.

Full Paper

Bibliographic reference.  Ainsworth, William / Meyer, Georg / Koreman, Jacques (1999): "Interrupted tones and repeated syllables", In ICPhS-14, 1819-1822.