Length Contrast and Covarying Features: Whistled Speech as a Case Study

International audience The status of covarying features to sound contrasts is a long-standing issue in speech: are they deliberately controlled by the speakers, or are they contingent automatic effects required by the defining features? We address this question by drawing parallels between the way gemination is implemented in spoken language and the way it is rendered in whistled speech. Audio materials were collected with five Berber whistlers in Morocco. The spoken and whistled data were composed of pairs of words contrasting singletons to geminates in different word positions. Compared to spoken forms, whistling, while adapting to the specific constraints imposed by the medium, transposes the basic strategies used in normal speech. As in normal speech, the primary and most salient acoustic attribute differentiating whistled singletons and geminates is closure duration. But duration is not used alone. Covarying secondary attributes are conveyed which may serve to enhance the primary correlate by contributing additional properties increasing the distance between the two lexical categories. These enhancing correlates may take on distinctive function in cases where the primary correlate is not implemented. This is, for instance, the case of higher frequency values in word-initial position where duration differences cannot be acoustically implemented using whistled speech.