Predicting children's real-ear-to-coupler differences based on tympanometric data
Ryan W McCreery1, Jeffery Crukley2, Anastasia Grindle3
1Audibility, Perception, and Cognition Laboratory, Boys Town National Research Hospital, Omaha, NE, USA.
Insights
Tympanometry can improve real-ear-to-coupler difference (RECD) predictions in children when direct RECD measurement is not possible. This method is particularly beneficial for children with abnormal middle ear status, enhancing hearing aid fitting accuracy.
Area of Science:
- Audiology
- Pediatric audiology
- Hearing science
Background:
- Paediatric hearing aid verification typically uses real-ear-to-coupler difference (RECD) measurements.
- Direct RECD measurements are not always feasible in children, potentially leading to inaccurate hearing aid fittings.
- Audiologists often possess tympanometry data that characterizes pediatric ear canal acoustics.
Purpose of the Study:
- To evaluate if tympanometry can enhance the prediction accuracy of measured RECD in children.
- To determine the clinical utility of tympanometry for improving RECD predictions when direct measurement is not possible.
Main Methods:
- Retrospective analysis of RECD and tympanometry data (admittance, peak pressure, equivalent ear-canal volume at 226 Hz) from 266 children with mild-to-severe hearing loss.
- Bayesian hierarchical regression modeling was employed to analyze the relationship between tympanometry and RECD.
Main Results:
- Age-based average RECD models achieved 3 dB accuracy in 54% (normal middle ear) and 50.6% (abnormal middle ear) of cases.
- Immittance-predicted RECD models showed higher accuracy, achieving 3 dB accuracy in 69.6% (normal middle ear) and 74.4% (abnormal middle ear) of cases.
- Immittance-predicted RECD was significantly more accurate than age-based predictions, especially in children with abnormal middle ear conditions.
Conclusions:
- Tympanometry offers a more accurate prediction of RECD compared to age-based averages, particularly for children with abnormal middle ear status.
- The study suggests that 226 Hz tympanometry can be clinically utilized to improve RECD predictions when direct measurement is not feasible.
- This approach can lead to more accurate hearing aid fittings for pediatric populations.
Objective:
Paediatric hearing-aid verification relies on measures of output obtained from the ear canal or in a coupler with the child's real-ear-to-coupler difference (RECD). Measured RECD cannot always be completed in children, leading to fitting inaccuracies. Audiologists often have tympanometry data that characterises the child's ear-canal acoustics. The goal of this study was to determine if tympanometry can be used to improve predictions of measured RECD.
Design:
A retrospective analysis of RECD and admittance, tympanometric peak pressure, and equivalent ear-canal volume from 226 Hz tympanometry collected as part of a longitudinal study of children with hearing loss were modelled with Bayesian hierarchical regression.
Study Sample:
Two-hundred sixty-six children with mild-to-severe hearing loss contributed data.
Results:
Age-based average RECD models were within 3 dB of measured RECD values in 54% of cases with normal middle ear status and 50.6% of cases with abnormal middle ear status. Immittance-predicted RECD were within 3 dB in 69.6% of cases with normal middle ear status and 74.4% of cases with abnormal middle ear status.
Conclusion:
Immittance-predicted RECD was more accurate than age-based average RECD, particularly in children with abnormal middle ear status. The findings suggest that 226 Hz tympanometry could be used clinically to improve predictions of measured RECD when it cannot be measured.
