Customized acoustic transform functions and their accuracy at predicting real-ear hearing aid performance

Area of Science:

• Audiology
• Acoustics
• Hearing Aid Technology

Background:

• Accurate hearing aid fitting requires precise measurement of the real-ear aided response.
• Traditional methods can be time-consuming and complex.
• Predictive models using acoustic transforms offer a potential alternative.

Purpose of the Study:

• To evaluate the validity of predicting the real-ear aided response.
• To assess the impact of customized acoustic transform functions on prediction accuracy.
• To determine if this predictive method can replace in situ measurements.

Main Methods:

• Measured real-ear hearing aid response and real-ear-to-coupler difference (RECD/HA2) in 24 normally hearing subjects.
• Obtained RECD/HA2 transform functions using insert earphones, hearing aid/pressure comparison, customized earmolds, and temporary tips.
• Calculated validity estimates by comparing derived and measured real-ear responses.

Main Results:

• Derived response closely matched measured response (within 5 dB) when using RECD/HA2 from a customized earmold for the specific ear.
• Using transforms from the opposite ear or temporary earmolds resulted in significant discrepancies.
• Both insert earphone and hearing aid RECD/HA2 transform functions demonstrated equal validity.

Conclusions:

• Predictive real-ear aided response using acoustic transforms is valid.
• Customized earmolds specific to the ear are crucial for accurate prediction.
• This derived response can serve as a substitute for in situ hearing aid response procedures.