 Are sounds private or public? Maclachlan (1989) argues that the sounds we hear are sensations (rather than, for instance, the pressure waves that cause auditory experiences). Such sensations are internal and private, and we experience them directly, or without apparent mediation. On Maclachlan’s account, we hear the ordinary things and happenings that are the sources of sounds only indirectly, by means of inference from auditory data.