Diotic and dichotic frequency discrimination thresholds in musicians and non-musicians: relationships between perception, musical ability and self-evaluated competence.

Pitch perception provides important information for musical and vocal communication. Numerous studies have shown that musical training and expertise are associated with better pitch processing, however, it is unclear what types of pitch percepts are plastic with music training. The current study addresses this issue by measuring discrimination thresholds of Musicians (n=20) and Non-musicians (n=18) to diotic (same sound to both ears) and dichotic (different sounds to each ear) stimuli created from four types of acoustic computations:1) pure sinusoidal tones, PT; 2) four-harmonic complex tones, CT; 3) iterated rippled noise, IRN; and 4) interaurally correlated broadband noise, called \"Huggins\" or \"dichotic\" pitch sounds, DP. Frequency Difference Limens (DLF) in each condition were obtained via a 3-alternative-forced-choice adaptive task requiring selection of the interval with the highest pitch, yielding the smallest perceptible fundamental frequency (F0) distance (in Hz) between two sounds. Music skill was measured by an online test of musical Pitch, Melody and Timing (International Laboratory for Brain Music and Sound Research, https://www.brams.org/en/onlinetest/). Musicianship, length of music experience and self-evaluation of musical skill were assessed by questionnaire. Results showed musicians had smaller DLFs in all four conditions and that thresholds were related to subjective and objective musical ability. In addition, self-report of musical ability was shown to be a significant variable in group classification, suggesting that the neurobehavioral profile of musicians includes self-evaluation of musical competence.