The Amplitude Modulation Structure of Japanese Infant- and Child-Directed Speech: Longitudinal Data Reveal Universal Acoustic Physical Structures Underpinning Moraic Timing

Tatsuya Daikoku, Usha Goswami

Infant-directed speech (IDS) is highly rhythmic, and in European languages IDS is dominated by patterns of amplitude modulation (AM) at ~2Hz (reflecting prosody) and ~5Hz (reflecti…