This pilot study aims at defining the notion of voice quality in Western lyrical singing and seeks significant and objective criteria to characterise it, from both cognitive and acoustic points of view. We have chosen an approach based on the semantic analysis of experts' discourses, as we assume that the description of the acoustic signal itself cannot fully account for the characterisation of voice quality and that this notion rather relies on the listeners' cognitive representations, which allow them to elaborate a meaningful judgement from acoustic properties. Therefore we started this study with a listening test, conducted with 11 singing teachers who freely described the voice quality of 18 western lyrical extracts, recorded from three different male singers. The linguistic analysis of these verbalisations brought information about the specific lexical resources (in French) involved in discourses, from which inferences can be made regarding the different conceptions of voice quality and the listening modes of the lyrical expert field. For these listeners, voice quality appeared to be a series of cues allowing to identify sound production, the singer's identity and his emotional state rather than just a set of acoustic characteristics perceived and processed for themselves. Next, an acoustic database was recorded with three lyrical male singers, who produced different voice qualities illustrating graduations of some verbal descriptors. These terms were selected for their relevance and from the previous linguistic analyses. The acoustic analyses of this database allowed us to put forward different sound descriptors which may be cues for listeners to perceive some aspects of voice quality, and which may account for the semantic overlap of several criteria for evaluating voice quality.