Real-ear measurement verification for open, non-occluding hearing instruments

Area of Science:

• Audiology
• Hearing Instrument Technology

Background:

• Real-ear measurements are crucial for accurate hearing aid fitting.
• Concurrent equalization can introduce errors due to sound leakage and digital feedback suppression (DFS).

Purpose of the Study:

• To investigate the accuracy of concurrent equalization versus stored equalization in real-ear measurements.
• To test hypotheses regarding underestimation of real-ear insertion gain with concurrent equalization and DFS.

Main Methods:

• Real-ear measurements using the modified pressure method were performed on 21 subjects.
• Comparisons were made between stored equalization and concurrent equalization techniques.
• The impact of digital feedback suppression (DFS) and open fittings was assessed.

Main Results:

• Concurrent equalization resulted in underestimated real-ear insertion gain, especially with open fittings.
• The error in gain measurement increased with higher levels of digital feedback suppression (DFS) benefit.
• Both tested hypotheses were supported by the study's findings.

Conclusions:

• Stored equalization is recommended over concurrent equalization for real-ear measurements of hearing instruments with DFS.
• Accurate fitting of hearing instruments with DFS and open fittings requires careful consideration of measurement techniques.