Auditory communication in domestic dogs: vocal signalling in the extended social environment of a companion animal

Domestic dogs produce a range of vocalisations, including barks, growls, and whimpers, which are shared with other canid species. The source–filter model of vocal production can be used as a theoretical and applied framework to explain how and why the acoustic properties of some vocalisations are constrained by physical characteristics of the caller, whereas others are more dynamic, influenced by transient states such as arousal or motivation. This chapter thus reviews how and why particular call types are produced to transmit specific types of information, and how such information may be perceived by receivers. As domestication is thought to have caused a divergence in the vocal behaviour of dogs as compared to the ancestral wolf, evidence of both dog–human and human–dog communication is considered. Overall, it is clear that domestic dogs have the potential to acoustically broadcast a range of information, which is available to conspecific and human receivers. Moreover, dogs are highly attentive to human speech and are able to extract speaker identity, emotional state, and even some types of semantic information

Why do large dogs sound more aggressive to human listeners: Acoustic bases of motivational misattributions

Previous research has highlighted that while human listeners are capable of estimating the body size of dogs using the acoustic components of their growls, they also rate growls from larger dogs as more being aggressive than growls from smaller dogs. The aim of this study was to investigate the relative contributions of two cues to body size, fundamental frequency (F0) and formant frequency dispersion (¿f) to perceived levels of aggression. We found that participants that had just made an accurate assessment of caller size based on these characteristics then misattributed aggressiveness levels on the basis of these same size-related acoustic cues. More specifically, stimuli in which F0 and/or ¿f were typical of larger dogs were rated as being more aggressive than stimuli typical of smaller dogs. Although both F0 and ¿f influenced aggressiveness ratings independently, their interaction also had a significant affect. These results are discussed with respects to the human tendency to generalise reliable between-class acoustic cues to within-class stimuli and the resulting potential for making perceptual misattributions. © 2010 Blackwell Verlag GmbH