Abstract : Because of structural variability, nominally identical objects of large-scale production may exhibit large variations in their behaviours. From a vibro-acoustic point of view, this variability has been observed and quantified and its origins have even been identified and located on several simple structures. But little is known about the consequences of this variability on the perception of sound emitted by the object. This work aims at evaluating the effects of structural variability on sound quality. As well as any other product component, sound is designed to fit the customer's expectations. The sound quality, resulting from this sound design process, can then be affected by structural dispersion. Initially, the variability of indicators commonly used to describe the perception of car interior noise was evaluated on a panel of vehicles whose dispersions were not controlled. The evolution of the sound quality was thus observed on a population of products. Then the study focused on a basic system for which several physical characteristics were finely controlled. Fractional factorial designs were used to measure the effects of the various factors on the perception of the noise emitted by this system. This methodology was used in a second case, for which sounds were synthesized. Different perceptual analyses (similarity evaluation and categorization) were carried out; their concordant results enabled to highlight the most influential factors. However, a last experiment showed that differences in sound identity could be perceived on a panel of identical objects but did not lead to confusions between nominally different objects.