Emphasis of this chapter is on one component of this, development of speech perception, particularly of the perception of phonemes.
Different languages use different sets of phonemes.
Data supporting this, for example, comes from study comparing perception of phonemic distinctions, some of which occur in both English and Hindi, others which only occur in Hindi. Without such exposure, initial abilities will be lost. This is called the maintenance-loss model . The central assumption of this model when applied to speech perception is that the neonate is equipped with sensitivity to all possible phonemes of all languages. The role of experience is to maintain sensitivity to only those ponemes that the infants hear.