Use of the California Consonant Test in evaluating hearing aids

Area of Science:

• Audiology
• Hearing Science
• Speech Perception

Background:

• Hearing aids are crucial for individuals with mild to moderate sensorineural hearing loss.
• Evaluating hearing aid performance requires sensitive and reliable speech tests.
• The California Consonant Test (CCT) is a tool used in audiological assessments.

Purpose of the Study:

• To evaluate the effectiveness of different hearing aids using the California Consonant Test (CCT).
• To determine how varying signal-to-noise ratios (S/Ns) affect CCT performance and hearing aid differentiation.
• To investigate the frequency of intralistener hearing aid differences under different noise conditions.

Main Methods:

• The California Consonant Test (CCT) was administered to twelve listeners with mild to moderate sensorineural hearing loss.
• The CCT was presented with white noise at signal-to-noise ratios (S/Ns) of +30 (quiet), +15, +5, and 0 dB.
• Hearing aid performance was assessed for each listener across the different S/Ns, with the quiet condition retested.

Main Results:

• Significant differences in mean test scores were observed between high and low S/Ns.
• Intralistener hearing aid differences were most frequently identified in the quiet condition (S/N +30 dB).
• Truncation errors were common at low S/Ns, and critical differences (≥5%) between hearing aids increased with improved S/N.

Conclusions:

• The sensitivity of the CCT is diminished, not enhanced, when mixed with noise.
• Noise does not improve the ability to differentiate between hearing aids using the CCT.
• Optimal hearing aid evaluation with the CCT occurs in quiet listening conditions.