Prosodic Modifications to Challenging Communicative Environments in Preschoolers.

Adapting one's speaking style is particularly crucial as children start interacting with diverse conversational partners in various communication contexts. The study investigated the capacity of preschool children aged 3-5 years (n = 28) to modify their speaking styles in response to background noise, referred to as noise-adapted speech, and when talking to an interlocutor who pretended to have hearing loss, referred to as clear speech. We examined how two modified speaking styles differed across the age range. Prosody features of conversational, noise-adapted, and clear speech were analyzed, including F0 mean (Hz), F0 range (Hz), energy in 1-3 kHz range (dB), speaking rate (syllables per second), and the number of pauses. Preschoolers adjusted their prosody features in response to auditory feedback interruptions (i.e., noise-adapted speech), while developmental changes were observed across the age range for clear speech. To examine the functional effect of the modified hyper-speech produced by the preschoolers, speech intelligibility was also examined in adult listeners (n = 30). The study found that speech intelligibility was higher in noise-adapted speech than in conversational speech across the preschool age range. A noticeable increase in speech intelligibility for clear speech was observed with the increasing age of preschool talkers, aligning with the age-related enhancements in acoustic prosody for clear speech. The findings indicate that children progressively develop their ability to modify speech in challenging environments, initiating and refining adaptations to better accommodate their listeners.