The voice contains a wealth of information relevant for successful and meaningful social interactions. Aside from speech, the vocal signal also contains paralinguistic information such as the emotional state and identity of the speaker. The three empirical chapters reported in this thesis research the perceptual processing of paralinguistic vocal cues. The first set of studies uses unimodal adaptation to explore the mental representation of emotion in the voice. Using a series of different adaptor stimuli -human emotional vocalisations, emotive dog calls and affective instrumental bursts- it was found that aftereffects in human vocal emotion perception were largest following adaptation to human vocalisations. There was still an aftereffect present following adaptation to dog calls, however it was smaller in magnitude than that of the human vocalisation aftereffect and potentially as a result of the acoustic similarities between adaptor and test stimuli. Taken together, these studies suggest that the mental representation of emotion in the voice is not species specific but is specific to vocalisations as opposed to all affective auditory stimuli. The second empirical chapter examines the supramodal relationship between identity and emotion in face-voice adaptation. It was found that emotional faces have the ability to produce aftereffects in vocal emotion perception, irrespective of the identity of the adaptor and test stimuli being congruent. However, this effect was found to be dependent upon the adapting stimuli being dynamic as opposed to static in nature. The final experimental chapter looks at the mechanisms underlying the perception of vocal identity. A voice matching test was developed and standardised, finding large individual differences in voice matching ability. Furthermore, in an identity adaptation experiment, absolute difference in aftereffect size demonstrated a trend towards significance when correlated with voice matching ability, suggesting that there is a relationship between perceptual abilities and the degree of plasticity observed in response adaptation.