The conspicuous vocalisations of a three-month old cat with craniocerebellar trauma were studied. A temporal coincidence between the improvement of the clinical condition and the change of the vocal utterances was observed. This vocal change could be observed in relevant acoustic parameters but it was seen more clearly in nonlinear phenomena (biphonation, subharmonics and deterministic chaos) in the cat's acoustic repertoire. The vocal change was also recognizable to the unaided ears.