Evaluation of a Frequency-Lowering Algorithm for Adults With High-Frequency Hearing Loss

Area of Science:

• Audiology
• Speech and Hearing Sciences
• Biomedical Engineering

Background:

• High-frequency hearing loss (HFHL) affects consonant perception, particularly sounds like /s, z/.
• Dead regions (DRs) in the cochlea can further impair audibility and speech understanding.
• Frequency-lowering algorithms aim to shift inaudible high-frequency sounds to audible lower frequencies.

Purpose of the Study:

• To evaluate the impact of a frequency-lowering algorithm (frequency composition, Fcomp) on speech perception in adults with HFHL.
• To assess Fcomp's effect on consonant identification, word-final /s, z/ detection, and sentence intelligibility in noise.
• To determine the subjective benefit of Fcomp for individuals with and without cochlear DRs.

Main Methods:

• A single-blind randomized crossover study compared hearing aid performance with Fcomp on and off.
• Ten adults with mild to severe HFHL, including those with DRs, participated.
• Outcome measures included audibility, speech perception tests, and a self-assessment questionnaire.

Main Results:

• Fcomp improved high-frequency audibility for 60% of participants.
• Word-final /s, z/ detection was significantly better with Fcomp on.
• No significant differences were found for consonant identification, sentence intelligibility, or subjective benefit.

Conclusions:

• Frequency composition (Fcomp) effectively enhances word-final /s, z/ detection in individuals with high-frequency hearing loss.
• The tested frequency-lowering algorithm did not yield overall improvements in consonant identification or subjective hearing ability.
• Further research may explore algorithm modifications for broader benefits in HFHL populations.