Speech-in-Noise Complaint After a 'Successful' Basic Fitting
A 68-year-old retired teacher returns three weeks after fitting bilateral receiver-in-canal devices. Her four-frequency pure-tone average is 42 dB HL right and 48 dB HL left, with a gently sloping high-frequency configuration. Word recognition in quiet was 88% right and 84% left at 65 dB HL. She reports that quiet conversation is fine but she 'gives up' at the restaurant where her family meets weekly, and she has stopped attending book club. Coupling is an open dome bilaterally. Real-ear measurement was not performed; the software's manufacturer-proprietary prescription was accepted and first-fit targets were not adjusted. She says the devices 'sound tinny' and that she turns the volume down in noisy places. She uses them about 6 hours per day.
1. What is the most likely technical explanation for her 'tinny' sound and her turning the volume down, and what would you check first?
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The most likely explanation is that the open dome plus unverified first-fit gain has left the high-frequency output excessive relative to what she can tolerate, while low-frequency amplification escapes the open canal. Her report of 'tinny' quality is a timbre complaint consistent with over-amplification in a band she is not accustomed to, and turning the volume down is her self-management strategy for loudness discomfort.
First check: probe-microphone real-ear aided response against a validated prescriptive target, plus real-ear occluded response to establish the open-dome vent effect. If the aided response exceeds target in the 2-4 kHz region, reduce gain there and re-measure. Also confirm the dome is seated and not migrating, and check whether the device's own volume control is locked or active. Do not simply lower overall gain; that would sacrifice speech audibility in the frequencies that matter for her word recognition scores.
2. She is a good candidate for verification but her primary complaint is noise, not quiet. What fitting change and verification step would you prioritize, and why?
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Prioritize directional microphone activation and a noise-management program, verified behaviorally rather than assumed. Because her word recognition is strong (88/84%), she has the cochlear reserve to benefit from a directional advantage, and her complaint is specific to a reverberant, multi-talker environment.
Steps: (1) Confirm the device is set to an automatic or fixed directional mode in the program she uses for the restaurant, and verify with a speech-in-noise measure or an aided speech recognition in noise test rather than relying on the manufacturer's claim. (2) Set the noise-reduction to a moderate level, since aggressive settings can degrade speech cues for listeners with high-frequency loss. (3) Re-verify with real-ear measurement in the directional condition, because directional microphones alter the aided response and can shift it off target. (4) Counsel on seating position relative to the talker. Document the pre/post speech-in-noise scores so the change is defensible.