Beskrivelse
Background:While a level increase typically gives better speech intelligibility (SI) at low presentation levels, it can lead to decreased SI at high levels. Termed rollover (RO), this phenomenon can negatively affect aided outcome. The research literature contains mixed findings regarding RO occurrence, possibly due to differences in methodology across studies, such as the use of different speech materials. Additionally, literature is sparse as regards ways of compensating for RO with hearing aids. In a previous study based on a simulated hearing aid, we introduced a fitting strategy termed “sweet-spot compression” (SSC). SSC aims at preventing RO by placing speech in that area of an individual’s performance- intensity function where intelligibility and listening comfort are high. While SSC could - unlike a clinical reference
condition - prevent RO at high levels, listeners preferred the reference condition at low levels. Here, we present follow-up research focused on developing methods for detecting and compensating for RO further.
Methods:
On the diagnostic side, we performed SI measurements at moderate to high presentation levels with different speech materials and hearing-impaired listeners with linear amplification. On the hearing-aid side, we implemented SSC on a wearable research hearing aid. Furthermore, we investigated a more precise determination of the individual sweet-spot area and revised the gain prescription to improve outcome at low levels.
Results:
We found clear RO with different speech materials at moderate to high levels. RO magnitude was comparable across levels and materials. Regarding the SSC evaluation, data collection is ongoing. We expect to find better outcomes with SSC than with a clinical reference condition at high levels, and comparable outcomes at low levels.
Discussion and Conclusion:
RO can occur already at moderate levels with different speech materials, making it relevant for real-world aided listening. Future research will focus on RO compensation in realistic test scenarios.
| Periode | 26. sep. 2024 |
|---|---|
| Begivenhedstitel | Auditory Science Meeting |
| Begivenhedstype | Konference |
| Grad af anerkendelse | International |