Monaural/binaural preferences: effect of hearing aid circuit on speech intelligibility and sound quality.

This investigation compared monaural and binaural hearing aid preferences of 15 adults with mild-to-moderately-severe bilaterally symmetrical sensorineural hearing losses. Subjects listened to connected discourse in quiet and background noise at 70 and 80 dB SPL with K-Amp, linear Class D, linear output limiting compression (OLC), Manhattan II, and linear asymmetrical peak clipping circuits (APC). In Experiment 1, subjects made judgments of sound quality and speech intelligibility in a modified paired-comparison paradigm during which they compared the monaural and binaural fittings of each circuit. In Experiment 2, subjects engaged in subjective ratings on a scale of 0 to 10. Subjects benefitted from improved sound quality and speech intelligibility in high-noise conditions when fit with binaural K-Amp, linear Class D, linear OLC, and Manhattan II circuits. Monaural listening was preferred with the APC circuit. Results indicate that improved sound quality and speech intelligibility may be obtained with binaural fittings of circuits that include high fidelity, low distortion, or increased head-room.