Perceiving differences in linguistic and non-linguistic pitch A pilot study with German congenital amusics

This study investigates the perception of pitch differences by seven German congenital amusics in speech and two types of non-speech material (sinusoidal waves and pulse trains). Congenital amusia is defined by a deficit in musical pitch perception, and recent studies indicate that at least a subgroup of congenital amusics also show deficits in linguistic pitch perception.
While previous studies employed pitch differences that occur in naturally spoken pairs of statements vs. echo questions to test the influence of amusia on linguistic pitch perception, the present study parametrically varied the pitch differences in steps of one semitone (from one to seven semitones). We further tested the influence of the direction of the pitch change, the length of the stimuli and the continuity of the pitch curve.
Our results show that amusics have difficulties detecting pitch changes both in non-linguistic stimuli and in speech. Furthermore, we found that amusics and controls performed better when the stimuli where discontinuous and the pitch was raised (instead of lowered). With respect to non-speech material, all participants performed better for pulse trains. The length of the stimuli did not influence the performance of the participants.