Encoding of timbre, speech, and tones: Musicians vs. non-musicians.

Summary In three experiments, musicians and non-musicians were compared with regard to auditory interference effects, while the kind of material (timbre, speech, and tones) and presentation rate were manipulated. The leading question is whether the musicians' familiarity with the processing of tonal pitch generalizes to a superiority in analyzing auditory features of other kinds of materials. By the manipulation of the presentation rate it is attempted to obtain interference effects at early vs. later stages of auditory processing. Results show that different materials cause different effects of presentation rate. For timbre, the effect was "linear", meaning the slower the presentation rate the better the performance, with the musicians outperforming the non-musicians. For speech, an effect of presentation rate could only be obtained with a very short stimulus duration. At a critical point, musicians were better than non-musicians in the identification of speech sounds. For tones, there was no effect of the presentation rate, but musicians were far better than non-musicians if the stimulus duration was sufficiently long. Key words: auditory processing, encoding, musicians, timbre, speech, tones Introduction What do musicians learn regarding auditory processing while undergoing extensive training in performing music? Musicians develop a high familiarity with some auditory features. In particular, they are very experienced in the processing of tonal pitch. It might be asked whether there are advantages in the analysis for other auditory features as well (for instance, auditory features of speech or timbre). Second, it might be asked at which stages of processing such advantage will show up. According to Cowan (1984), a distinction can be made between short vs. long auditory storage, the former reflecting an initial encoding process, and the latter consisting of memory traces for auditory features. The present work examines interference effects for short vs. long auditory storage by a manipulation of the presentation rate and stimulus duration. To test for the specificity of possible advantages for the musicians as compared to non-musicians, interference effects for timbre, speech, and tonal materials are tested. The interference paradigm that is used in the present experiments was first established by Deutsch (1970, 1975). The paradigm requires the comparison of two tones separated by a 5 sec interval containing 6 intervening tones. The purpose of her research was to demonstrate the specificity and systematicity in auditory short term storage with nonverbal materials (see Deutsch, 1975, for a review). In one of the first experiments with this paradigm, Deutsch (1970) used tones and speech (numbers) as distractors. She found that the intervening tones affected the tone comparison performance whereas speech distractors had no effect at all. Deutsch (1970) pointed out that this pattern of interference effects was highly specific in nature and could not be explained by the existence of an amodal short term memory for all kinds of materials. Pechmann and Mohr (1992) compared the performance of musicians and non-musicians using the single tone comparison paradigm Tones, speech and visual matrices served as intervening stimuli. Whereas the performance was equally poor in musicians and nonmusicians when tones were presented during the inter-stimulus interval, musicians outperformed the non-musicians with speech distractors as well as with visual distractors. Thus, interference effects occurred between different (or dissimilar) materials, but these interference effects were modulated by the musicians' familiarity with the primary tonal comparison task. The original paradigm of Deutsch (1970) presumably examines interferences effects in working memory. The time skeleton (200 ms stimulus duration plus 300 ms pause for each of the tones) leaves sufficient time to form an internal representation of S1 before the intervening stimuli occur. …