Musical experience limits the degradative effects of background noise on the neural processing of sound

Abstract

Musicians have lifelong experience parsing melodies from background harmonies, which can be considered a process analogous to speech perception in noise. To investigate the effect of musical experience on the neural representation of speech-in-noise, we compared subcortical neurophysiological responses to speech in quiet and noise in a group of highly trained musicians and nonmusician controls. Musicians were found to have a more robust subcortical representation of the acoustic stimulus in the presence of noise. Specifically, musicians demonstrated faster neural timing, enhanced representation of speech harmonics, and less degraded response morphology in noise. Neural measures were associated with better behavioral performance on the Hearing in Noise Test (HINT) for which musicians outperformed the nonmusician controls. These findings suggest that musical experience limits the negative effects of competing background noise, thereby providing the first biological evidence for musicians' perceptual advantage for speech-in-noise.

Figure 1.

Auditory brainstem responses for musician and nonmusician groups. A–D, The speech-evoked auditory brainstem response in quiet [musicians (A) and nonmusicians (B)] and in background noise [musicians (C) and nonmusicians (D)]. Musicians demonstrated a greater degree of similarity between their responses in quiet and noise, suggesting that their responses are less degraded by the addition of background noise, unlike nonmusicians. A group comparison revealed a significant difference with musicians having a greater quiet-to-noise correlation than nonmusicians (F_(1,30) = 6.082; p = 0.02). The musicians are plotted in black and the nonmusicians in gray.

Figure 2.

Group onset and transition differences. A, The stimulus /da/ and an individual (musician) response waveform. The stimulus waveform has been shifted forward in time (∼8 ms) to align the stimulus and response onsets. The two major peaks corresponding to the onset (labeled 1) and the formant transition (labeled 2) of the stimulus are circled. B, C, Musicians (black) and nonmusicians (gray) have equivalent onset (B) and transition (C) peak latencies in the quiet condition. However, although both groups show an increase in onset and transition peak latency in the noise condition, the musicians are less affected. **p < 0.01. Error bars represent ±1 SE.

Figure 3.

Stimulus-to-response correlation and harmonic representation. A, Musicians (black) show greater stimulus-to-response correlation in the presence of background noise, suggesting their brainstem responses are more resistant to the degradative effects of noise. B, C, The results of a fast Fourier transform show that, although musicians have equivalent encoding of the f₀ in both quiet (B) and noise (C), they demonstrate greater encoding of the harmonics (whole-integer multiples of the f₀). The inset bar graphs represent the f₀ and the summed representation of H₂–H₁₀ in both quiet and noise, respectively. D, E, Finally, a greater summed representation of H₂–H₁₀ was related to a higher stimulus-to-response correlation for both quiet (D) and noise (E) conditions. In quiet, the groups are relatively equivalent on these measures; however, in noise, there is a clear separation, with the musicians having both greater harmonic amplitudes and also higher stimulus-to-response correlations. **p < 0.01. Error bars represent ±1 SE.

Figure 4.

Relationship between speech perception in noise (HINT) and neurophysiological measures. A, B, Earlier onset (A) and transition (B) peak latencies are associated with better HINT scores. C, Likewise, a higher stimulus-to-response correlation between the eliciting speech stimulus /da/ and the brainstem response to this sound in the presence of background noise was found to correspond to a better HINT score. A more negative HINT SNR score is indicative of better performance. The black circles represent musicians, and the gray circles represent nonmusicians.