Which dB SPL level is used to determine full-on gain for hearing aids?

The determination of full-on gain for hearing aids is typically based on a 50 dB SPL level. This level is used because it represents a moderate input sound pressure level that aligns well with typical conversational speech sounds. At this level, hearing aids are tested to provide maximum amplification prior to any limiting occurring, which reflects their performance in real-world communication situations. It allows for effective analysis and adjustment of a hearing aid's gain settings, ensuring that users receive adequate amplification for speech and environmental sounds without distortion or discomfort.

Choosing a lower or higher dB SPL level could lead to either underestimating or overestimating the gain needed for effective hearing assistance, which is why 50 dB SPL is standard in industry practices for assessing full-on gain.