The different functions of sound

William Gaver suggests that there are two ways in which we hear sounds: through ‘musical listening’, which focuses on the perceptual quality of sounds such as pitch and loudness, and via ‘everyday listening’ which is concerned with attending to events such as a door banging or a siren blaring. To these two categories should be added the perception and cognition of speech sounds which, research indicates, is processed through dedicated neurological pathways.

That is to say, in Western cultures at least, sound fulfils three main functions, which, it is hypothesised, become gradually more delineated in the early years, and are readily conceptually distinguishable by adults. Hence a developmental model of functional sound processing can be constructed as follows, in which the domain of PMLD is taken to extend from the last three months of ‘typical’ intrauterine development to the end of the first year.

The five phases that are identified will be explained in due course. Clearly, further empirical work may verify what is proposed here or indicate that modification is necessary. For now, it offers a workable hypothesis from which to proceed.