Effects of Long-Term Musical Training on Cortical Auditory Evoked Potentials

Abstract

Objective Evidence suggests that musicians, as a group, have superior frequency resolution abilities when compared to non-musicians. It is possible to assess auditory discrimination using either behavioral or electrophysiologic methods. The purpose of this study was to determine if the auditory change complex (ACC) is sensitive enough to reflect the differences in spectral processing exhibited by musicians and non-musicians. Design Twenty individuals (10 musicians and 10 non-musicians) participated in this study. Pitch and spectral ripple discrimination were assessed using both behavioral and electrophysiologic methods. Behavioral measures were obtained using a standard three interval, forced choice procedure and the ACC was recorded and used as an objective (i.e. non-behavioral) measure of discrimination between two auditory signals. The same stimuli were used for both psychophysical and electrophysiologic testing. Results As a group, musicians were able to detect smaller changes in pitch than non-musicians. They also were able to detect a shift in the position of the peaks and valleys in a ripple noise stimulus at higher ripple densities than non-musicians. ACC responses recorded from musicians were larger than those recorded from non-musicians when the amplitude of the ACC response was normalized to the amplitude of the onset response in each stimulus pair. Visual detection thresholds derived from the evoked potential data were better for musicians than non-musicians regardless of whether the task was discrimination of musical pitch or detection of a change in the frequency spectrum of the rippled noise stimuli. Behavioral measures of discrimination were generally more sensitive than the electrophysiologic measures; however, the two metrics were correlated. Conclusions Perhaps as a result of extensive training, musicians are better able to discriminate spectrally complex acoustic signals than non-musicians. Those differences are evident not only in perceptual/behavioral tests, but also in electrophysiologic measures of neural response at the level of the auditory cortex. While these results are based on observations made from normal hearing listeners, they suggest that the ACC may provide a non-behavioral method of assessing auditory discrimination and as a result might prove useful in future studies that explore the efficacy of participation in a musically based, auditory training program perhaps geared toward pediatric and/or hearing-impaired listeners.

A Preliminary Study of the Effects of Attentive Music Listening on Cochlear Implant Users’ Speech Perception, Quality of Life, and Behavioral and Objective Measures of Frequency Change Detection

“…Numerous studies involving normal-hearing listeners have reported positive effects of music training on pitch perception. For instance, our group and other researchers have reported that musicians, who undergo years of music training, exhibit superior performance of pitch perception and better neurophysiological responses relative to non-musicians (Besson et al, 2007;Kraus et al, 2009;Itoh et al, 2012;Fuller et al, 2014;Brown et al, 2017;Liang et al, 2018). Such long-term music training may be expanded to the speech domain and positively affect speech perception in noise (Parbery-Clark et al, 2009;Baskent and Gaudrain, 2016).…”

“…Cortical auditory evoked potentials can be evoked by the stimulus onset (onset CAEP) and a change within a stimulus (acoustic change complex or ACC, Friesen and Tremblay, 2006;Martin, 2007;Mathew et al, 2017;Liang et al, 2018). Unlike the onset CAEP that reflects cortical detection of stimulus onset, the ACC reflects a listener's cortical processing of acoustic changes and it is corresponding to auditory discrimination ability (He et al, 2012;Kim, 2015;Brown et al, 2017). Compared to the MMN, the ACC is more time-efficient (every stimulus contributes to the ACC and thus a smaller number of stimulus trials are required), has a larger and more stable amplitude, and has better test-retest reliability (Kim, 2015).…”

Changes in Speech-Related Brain Activity During Adaptation to Electro-Acoustic Hearing

“…The early N1-P2 response is typically elicited by spectrally complex acoustic signals including words. It can be recorded from CI users and has been shown to be modulated by background noise in NH and CI listeners (22)(23)(24)32). The N1-P2 response consists of a negative deflection, peaking about 100 ms after stimulus onset (N1) and a positive deflection at around 200 ms (P2).…”

“…After CI implantation, N1 shows rapid improvement and stabilizes over the first 8-15 weeks of CI experience for an auditory discrimination task (26). Furthermore, it has been suggested that the N1-P2 complex can be used to monitor neurophysiological changes during auditory training in CI users (32,34). In addition, auditory cortex activation is dependent on the learned subjective quality of sounds, evidenced by enhanced and faster early processing of speech sounds compared to their non-speech counterparts, and by the stronger cortical response to familiar than to unfamiliar phonemes (29,30).…”

Musicians do not benefit from differences in fundamental frequency when listening to speech in competing speech backgrounds

“…However, other studies found auditory working memory to be similar for groups of musicians and non-musicians 11 , 25 . It is also possible that the musician advantage is related to the enhanced pitch discrimination abilities previously found in musicians 1 – 3 . In one study, the target was distinguished from the masker talker by introducing differences in either fundamental frequency (F0, the acoustic correlate of pitch) or vocal tract length, and an advantage was observed in all conditions 19 .…”