UCL Ear Institute


Musical chord discrimination in cochlear implant users

Music perception and enjoyment is a challenging area for users of cochlear implants (CIs). The limited spectral resolution is thought to lead to impaired perception of pitch, limiting accurate perception of music (Lassaletta et al, 2008). Mirza et al (2003) found in a questionnaire study that average self-reported enjoyment of music fell dramatically post-implantation.

The cochlear implant speech processing strategy of ‘current steering’ delivers current simultaneously to two electrodes, allowing additional intermediate pitches to be perceived. This technique is employed in the Advanced Bionics HiRes 90K device, which has multiple independent current sources allowing it to create these virtual channels. This has important implications not only for the perception of pitch in cochlear implant users, but for their perception and enjoyment of music as well.

These pilot tests use the discrimination of pitch changes in musical chords to examine the pitch and music perception abilities of users of CI devices both with and without virtual channels. Results will guide further research into the role of virtual channels in the perception of pitch.

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