NAL-NL2 Prescriptive Targets for Bone Conduction Devices With an Adaptation to Device Constraints in the Low Frequencies.
Martijn Toll, Gertjan Dingemanse
PMID 35622973WHAT IT FOUND
Bone conduction device users rated a moderate low-frequency reduction better than the setting with the most low-frequency output for own voice, while music was better with more low-frequency output.
Speech scores stayed high, but speech in noise remained below normal hearing norms.
Key findings
01For music, the optimal audibility setting was rated significantly better than the reduced audibility, least distortion setting.
02For the participants' own voice, the moderate audibility and reduced audibility settings were rated significantly better than the optimal audibility setting.
03The reduced audibility setting gave significantly better speech reception thresholds in noise than the optimal audibility setting, while all settings were significantly worse than the normal hearing norm.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Participants tried the settings for only 1 to 2 hours in a laboratory, so longer-term real-life acceptance and benefit are unknown. The study used one bone conduction device model, so results may not apply to devices with different resonance frequency or maximum output. The participants had near-normal cochlear function to only slight sensorineural hearing loss, so people with larger cochlear losses may need different settings. The sound quality test used a small number of sounds and a short listening time, so preferences may not cover all everyday listening. High-frequency output could not always be fitted to target because of feedback and elevated thresholds at 4 and 8 kHz in some participants. Speech-in-noise scores were worse than the normal hearing norm for all settings, so the study does not show that these settings restore normal hearing-in-noise performance.
Declared interests
Oticon Medical funded the study. The authors declared no conflicts of interest.
The easy way to misread this
Do not conclude that the moderate adaptation is proven for everyday use. Participants tried the settings for only 1 to 2 hours in a laboratory, and the study used one bone conduction device model.