The musician effect: does it persist under degraded pitch conditions of cochlear implant simulations?

Christina D Fuller,John J Galvin,Rolien H Free,Deniz Baåÿkent,Bert Maat

doi:10.3389/fnins.2014.00179

Abstract

Cochlear implants (CIs) are auditory prostheses that restore hearing via electrical stimulation of the auditory nerve. Compared to normal acoustic hearing, sounds transmitted through the CI are spectro-temporally degraded, causing difficulties in challenging listening tasks such as speech intelligibility in noise and perception of music. In normal hearing (NH), musicians have been shown to better perform than non-musicians in auditory processing and perception, especially for challenging listening tasks. This “musician effect” was attributed to better processing of pitch cues, as well as better overall auditory cognitive functioning in musicians. Does the musician effect persist when pitch cues are degraded, as it would be in signals transmitted through a CI? To answer this question, NH musicians and non-musicians were tested while listening to unprocessed signals or to signals processed by an acoustic CI simulation. The task increasingly depended on pitch perception: (1) speech intelligibility (words and sentences) in quiet or in noise, (2) vocal emotion identification, and (3) melodic contour identification (MCI). For speech perception, there was no musician effect with the unprocessed stimuli, and a small musician effect only for word identification in one noise condition, in the CI simulation. For emotion identification, there was a small musician effect for both. For MCI, there was a large musician effect for both. Overall, the effect was stronger as the importance of pitch in the listening task increased. This suggests that the musician effect may be more rooted in pitch perception, rather than in a global advantage in cognitive processing (in which musicians would have performed better in all tasks). The results further suggest that musical training before (and possibly after) implantation might offer some advantage in pitch processing that could partially benefit speech perception, and more strongly emotion and music perception.

Highlights

In normal hearing (NH), musicians show advantages in auditory processing and perception, especially for challenging listening tasks
Note that in some cases, median and 25th/75th percentiles could not be displayed because performance was good amongst participants; as such, only error bars and outliers are displayed
The effects of timbre were small in the Cochlear implants (CIs) simulation, as performance was generally similar between the piano and the organ

Summary

Introduction

In normal hearing (NH), musicians show advantages in auditory processing and perception, especially for challenging listening tasks. Some transfer of musical training to better speech understanding in noise has been observed, evidence for such transfer has been mixed (Parbery-Clark et al, 2009; Kraus and Chandrasekaran, 2010; Ruggles et al, 2014) This “musician effect” might be due to better processing of voice pitch cues that can help to segregate speech from noise (Micheyl et al, 2006; Besson et al, 2007; Oxenham, 2008; Deguchi et al, 2012), suggesting that there may be differences between musicians and non-musicians in terms of sound processing at lower levels of the auditory system. The musician effect has been studied in NH listeners under conditions in which the spectro-temporal fine structure cues important for complex pitch perception are fully available It is not yet known if this effect would persist when the acoustic signal is degraded and when the pitch cues are less available, whether due to signal processing and transmission in hearing devices or by hearing impairment. While the CI users can understand speech transmitted through the device to www.frontiersin.org

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