Background: Although most prevalent in childhood, the acquisition of new words in oral vocabulary takes place right across the lifespan. Of the many factors that influence oral vocabulary learning, one extrinsic factor is the listening environment. The current study aimed to examine whether the presence of noise impacts oral vocabulary learning in…

Children are adept at learning their language's speech-sound categories, but just how these categories function in their developing lexicon has not been mapped out in detail. Here, we addressed whether, in a language-guided looking procedure, 2-year-olds would respond to a mispronunciation of the voicing of the initial consonant of a newly learned…

This longitudinal study assessed three acoustic components of maternal infant-directed speech (IDS) -- pitch, affect, and vowel hyperarticulation -- in relation to infants' age and their expressive vocabulary size. These three individual components were measured in IDS addressed to infants at 7, 9, 11, 15, and 19 months (N = 18). All three…

We investigate whether infant-directed speech (IDS) could facilitate word form learning when compared to adult-directed speech (ADS). To study this, we examine the distribution of word forms at two levels, acoustic and phonological, using a large database of spontaneous speech in Japanese. At the acoustic level we show that, as has been documented…

Speech production and perception are inextricably linked systems. Speakers modify their speech in response to listener characteristics, such as age, hearing ability, and language background. Listener-oriented modifications in speech production, commonly referred to as clear speech, have also been found to affect speech perception by enhancing…

Infants begin to segment words from fluent speech during the same time period that they learn phonetic categories. Segmented words can provide a potentially useful cue for phonetic learning, yet accounts of phonetic category acquisition typically ignore the contexts in which sounds appear. We present two experiments to show that, contrary to the…