Comparison of the CAM2A and NAL-NL2 hearing-aid fitting methods for participants with a wide range of hearing losses

Abstract

Objective: To compare preferences for sounds processed via a simulated five-channel compression hearing aid fitted using CAM2A and NAL-NL2. Design: Within a trial, the same segment of sound was presented twice, once with CAM2A settings and once with NAL-NL2 settings, in random order. The participant indicated which one was preferred and by how much. Stimuli included female and male speech in quiet and four types of music. The compression speed was slow or fast and the input sound level was 50, 65, or 80 dB SPL. Study sample: Sixteen experienced hearing-aid users with a wide range of sensorineural hearing losses. Results: For both compression speeds, CAM2A was slightly preferred over NAL-NL2 for input levels of 65 and 80 dB, but NAL-NL2 was slightly preferred at 50 dB SPL. Conclusions: Preferences for CAM2A relative to NAL-NL2 vary with input level. The results suggest that preferences for CAM2A might be increased by using lower gains for high frequencies and low input levels.

Key Words:

• Hearing aids
• fitting methods
• preference judgments
• compression speed

Acknowledgements

This work was supported by the MRC (UK, Grant number G0701870). We thank Michael Stone for writing the software for the hearing-aid simulator. Brian Glasberg collaborated in revising the CAM2A software to produce the CAM2B software. We thank three reviewers for helpful comments on an earlier version of this paper.

Declaration of interest

The authors receive royalties from sales of the CAM2 fitting software.