Open-Set Phoneme Recognition Performance With Varied Temporal Cues in Younger and Older Cochlear Implant Users

Area of Science:

• Audiology
• Neuroscience
• Speech-Language Pathology

Background:

• Age is a known factor influencing cochlear implant (CI) benefits.
• Older CI users may experience a performance gap due to central auditory temporal processing deficits.
• Temporal processing is crucial for phoneme recognition, especially with limited signal information.

Purpose of the Study:

• To investigate the effect of chronological age on phoneme recognition performance in CI users.
• To examine how varying temporal information in speech signals affects phoneme recognition across different age groups.
• To understand the role of age and duration of deafness in utilizing temporal cues for speech perception.

Main Methods:

• Phoneme recognition was assessed in 20 CI participants (ages 27-85).
• Stimuli varied in temporal information, presented at different stimulation rates (500-1800 pps) and envelope modulation frequencies (50 Hz, unfiltered).
• Speech stimuli used were word pairs with temporal contrasts, delivered via an eight-channel continuous interleaved sampling strategy.

Main Results:

• Duration of deafness was the primary predictor of phoneme recognition, with longer durations correlating to poorer performance.
• Chronological age did not significantly predict phoneme recognition across any tested condition.
• Duration of deafness interacted with envelope filtering; shorter durations allowed better use of higher frequency modulations.

Conclusions:

• Chronological age was not a significant predictor of phoneme recognition performance in this CI user cohort.
• Longer duration of deafness was strongly associated with impaired ability to leverage temporal signal information.
• Findings suggest that duration of deafness, rather than age, is a critical factor in temporal processing deficits affecting speech recognition in CI users.