Overcoming the Challenge of Singing Among Cochlear Implant Users: An Analysis of the Disrupted Feedback Loop and Strategies for Improvement

Abstract

Background: Cochlear implants (CIs) are transformative neuroprosthetics that restore speech perception for individuals with severe-to-profound hearing loss. However, temporal envelope cues are well-represented within the signal processing, while spectral envelope cues are poorly accessed by CI users, resulting in substantial deficits compared to normal-hearing individuals. This profoundly impairs the perception of complex auditory stimuli like music and vocal prosody, significantly impacting users' quality of life, social engagement, and artistic expression. Methods: This narrative review synthesizes research on CI signal-processing limitations, perceptual and production challenges in music and singing, the role of the auditory-motor feedback loop, and strategies for improvement, including rehabilitation, technology, and the influence of neuroplasticity and sensitive developmental periods. Results: The degraded signal causes marked deficits in pitch, timbre, and vocal emotion perception. Critically, this impoverished input functionally breaks the high-fidelity auditory-motor feedback loop essential for vocal control, transforming it from a precise fine-tuner into a gross error detector sensitive only to massive pitch shifts (~6 semitones). This neurophysiological breakdown directly causes pervasive pitch inaccuracies and melodic distortion in singing. Despite these challenges, improvements are possible through advanced sound-processing strategies, targeted auditory-motor training that leverages neuroplasticity, and capitalizing on sensitive periods for auditory development. Conclusions: The standard CI signal creates a fundamental neurophysiological barrier to singing. Overcoming this requires a paradigm shift toward holistic, patient-centered care that moves beyond speech-centric goals. Integrating personalized, music-based rehabilitation with advanced CI programming is essential for improving vocal production, fostering musical engagement, and ultimately enhancing the overall quality of life for CI users.

Keywords: auditory–motor feedback loop; aural rehabilitation; cochlear implant; music perception; neuroplasticity; pitch perception; prosody; singing; vocal production.

Figure 1

Cochlear Implant (CI) vs. Normal Hearing (NH) Spectrography and Waveforms. All figures were created with an 18 s clip of Gershwin’s “Rhapsody in Blue”. CI audio simulation created through a vocoder chain utilizing frequency assignment to pure tones. (A) displays the acoustic (NH) waveform on the left-hand side of the diagram in comparison to the right-hand electric (CI) waveform. (B) displays both electric and acoustic spectrograms, with frequencies ranging from 40 Hz to 23 kHz. (C) is a spectrogram limited to a range of 40 Hz to 1.2 kHz, focusing on the traditional melodic range and emphasizing the loss of melodic elements in CI hearing.

Figure 2

The broken auditory–motor feedback loop when individuals who use cochlear implants (CI) try to sing. Sound produced by the lips (vocalization) travels to the implanted ear(s) with profound hearing loss, but the technological limitations of the CI (device and/or sound processing) lead to inaccurate perception of pitch. In individuals with normal-hearing ears, the brain is able to compare the produced sound to the intended sound and make immediate adjustments to pitch as needed, correcting the intonation of the notes sung next. However, because CI users cannot accurately hear musical sound (afferent or sensory signal), they have impaired pitch adjustment that leads to a cycle of out-of-tune singing (efferent or motor response).

Figure 3

A Holistic Rehabilitation Plan for Music and Prosody Perception in Cochlear Implant (CI) Users. CBAT = computer-based auditory training.