Acoustic characteristics of clear speech and noise-adapted speech in preschoolers

Abstract

It is well-known that adults can change their speaking styles to make them more intelligible for their listeners. However, we do not know how young children can achieve the ability to alter their speech. The study investigated if preschoolers can modify their speech responding to challenging communicative situations. Children performed “spot the difference” tasks (Baker and Hazan, 2011) with a communication partner to elicit conversational speech (CO), noise-adapted speech (NAS), and listener-oriented clear speech (CL) production. We examined the acoustic features of the three speaking styles in 28 preschoolers. Suprasegmental features of CO, NAS, and CL were analyzed, including F0 (Hz), F0 range (Hz), energy in the 1–3kHz range(dB), and speech rate(syllables per second). Results showed conversation-to-NAS modifications for all four acoustic measures in all age groups. For conversation-to-CL modifications, all age groups decreased their speaking rate. The 5-year-olds increased their energy and pitch for CL. The 4-year-olds also increased the pitch for CL. The 3-year-olds did not change pitch and decreased energy for CL, which displays the opposite tendencies of adults. Preschoolers appear to be aware on some level of the challenging nature of communicative environments. They undergo ongoing development of speech modification for their listeners.