Perceptual Learning on Melodic Palindromes: Evidence That Timbre Affects Pitch Memory

1. Perceptual Learning on Melodic Palindromes: Evidence That Timbre Affects Pitch Memory Nestor Matthews1, Kristin M. Reardon1&2, & Obiageli Uguru1 Department of Psychology, Denison University1, The College of William & Mary2 Poster #24 Results Introduction Palindrome A Palindrome B Before training, pitch memory was equally precise for acoustically forward and acoustically backward melodic palindromes (F(1,17) = 1.882, p=.188, n.s., partial eta-squared = 0.10). However, after training exclusively for five days on acoustically forward palindromes, precision was significantly greater for forward-played than for backward-played palindromes (F(1,17) = 37.558, p <0.001, partial eta squared = 0.688). Indeed, the training (pre versus post) by timbre (forward versus backward) interaction was significant ( F(1,17) = 21.996 p <0.001, partial eta squared = 0.564). It should be noted, though, that significant learning also occurred on the non-trained (i.e., acoustically backward) timbre (F(1,17) = 28.536, p <0.001, partial eta squared = 0.627). Thus the practice effects had both a timbre-independent and a timbre-specific component. People with no musical training can identify the original musical key of popular tunes with precision1. To what extent does this ability depend on timbre- the subjective quality of sound that is cued by acoustic transients2? Here we explored the role of timbre in pitch memory by using melodic palindromes. Acoustically Forward Method Acoustically Backward Eighteen Denison University undergraduates each completed one pre-training session, five training sessions, and one post-training session. During the pre-training, participants learned to distinguish two melodic palindromes from each other. Palindrome A (1-7-4-4-7-1) was in the key of E major, while Palindrome B (1-7-5-5-7-1) was in the key of A-flat major. Subsequently, participants listened to pitch-shifted versions of the two palindromes, and judged each such variation to be either sharper or flatter than the original. Half the stimuli were played forward, and half were played backward, randomly. Reversing the direction of play altered the micro-acoustic structure (the pattern of ‘ramps’ and ‘damps’) and hence, the timbre. During the five training sessions, only forward versions were played. Finally, the post-training session was identical to the pre-training session; both forward and backward versions of the palindromes were tested. Thresholds Across Training Sessions Pre versus Post Discussion In principle, the ability to identify a song’s original musical key could be based solely on melodic interval. However, our finding that a significant portion of the practice effects was specific to the trained micro-acoustic structure suggests that timbre plays a significant role in generating precise pitch memories. * Sensitivity Across Training Sessions Pre versus Post * References 1.Schellenberg & Trehub (2003) PMID: 12741751 2. Thayer, R.J. (1974). The effect of the attack transient on aural recognition of instrumental timbres. Psychology of Music, 2, 39-52. http://www.denison.edu/~matthewsn/percetpuallearningmusicalkeyepa2009.html