The Effect of Tactile Cues on Auditory Stream Segregation Ability of Musicians and Nonmusicians.

(ProQuest: . denotes formulae omitted.)Western music is often composed of multiple melodic streams that combine to produce a complex structure that gives a particular piece its unique depth and quality. In order to appreciate the interplay of melodic streams, listeners need to be able to first segregate them. Unfortunately, people with hearing loss typically experience great difficulty in doing so primarily due to an impoverishment of their perceptual cues (Oxenham, 2008). This makes music appreciation very challenging for these listeners. For hearing-impaired people whose auditory pathway is fundamentally limited, such as those who use a cochlear implant, it is important to explore sensory substitution as a possible means of enhancing stream segregation and music perception. Recent studies have shown that visual cues can aid hearing-impaired people, and more specifically cochlear implant listeners, in better segregating two musical streams (Innes-Brown, Marozeau, & Blamey, 2011; Marozeau, InnesBrown, Grayden, Burkitt, & Blamey, 2010). We therefore hypothesize that tactile information can be used in a similar way. This paper describes a first study which tests the effect of tactile cues on segregation ability in normal hearing listeners as function of their musical background.Segregation of a melodic stream is made possible by both bottom-up and top-down processes. Bottom-up processes are derived from perceptual cues such as pitch, timbre, and loudness (Bregman, 1990; Marozeau, Innes-Brown, & Blamey, 2010). Topdown processes are derived from cognitive processes involving memory, expectation, musical training, and attention (Carlyon, Cusack, Foxton, & Robertson, 2001). Auditory stream segregation can also be influenced by cross-modal interaction (Carlyon, Plack, Fantini, & Cusack, 2003). Marozeau et al. (2010) have demonstrated that visual cues can improve the streaming ability in both musicians and nonmusicians. Carlyon et al. (2003) has also demonstrated both cross-modal and nonsensory influences on auditory streaming.It is not uncommon for a listener to describe the sensation of "feeling music. " Tactile information can add to temporal cues emphasizing the rhythm within a piece (Fraisse, 1981), and can generate a strong sensation of rhythm on its own (Brochard, Touzalin, Despres, & Dufour, 2008). Huang, Gamble, Sarnlertsophon, Wang, and Hsiao (2013) demonstrated that meter is perceived similarly well (70%-85%) when either tactile or auditory cues are presented alone, and that in bimodal mode auditory and tactile cues are integrated to produce coherent meter percepts. It might therefore be hypothesized that tactile information can have an effect on the perception of the musical streams.Musical training is known to have a positive effect on segregation ability (Strait, Kraus, Parbery-Clark, & Ashley, 2010). The effect of cross-modal information on stream segregation can therefore interact with musical training. In order to isolate and understand the interaction between tactile cues and auditory stream segregation ability normal hearing listeners with and without musical experience were assessed.MethodParticipantsTwenty-four participants (12 musicians and 12 nonmusicians, with approximate age average of 27 years old, ranging from 21 to 35 years old) were recruited using social networks in the musician and nonmusician communities. All musicians were full-time professional performers. Nine of them had a formal tertiary education in music and could read music proficiently. The other three were professional flamenco players with an expert level of musicianship but a weaker ability to read music. All the nonmusician participants were unable to play an instrument, and had limited musical training. All participants reported normal hearing and had hearing thresholds at octave frequencies from 125 Hz to 8 kHz below 20 dB HL. Participants also reported normal tactile sensation in their fingertips. …