Relationship of Head Circumference and Age in the Prediction of the Real-Ear-to-Coupler Difference (RECD)
Kelli M Watts1, Marlene Bagatto2, Sandra Clark-Lewis1
1Auburn University, Auburn, AL.
Insights
Head circumference (HC) can predict real-ear-to-coupler difference (RECD) values in children and adults when individual measurements are not feasible. This offers a reliable alternative to age-based predictions for hearing instrument fitting.
Area of Science:
- Audiology
- Biomedical Engineering
- Pediatric Healthcare
Background:
- Pediatric hearing instrument fitting relies on real-ear-to-coupler difference (RECD) measurements.
- When RECDs are unobtainable, age-based predictions are used.
- Head circumference (HC) shows potential as an alternative predictor for RECDs in children.
Purpose of the Study:
- To evaluate head circumference (HC) as a predictor for real-ear-to-coupler difference (RECD) values.
- To assess HC's predictive capability across infants, children, and adults.
Main Methods:
- Correlational study design involving 278 infants and children and 109 adults.
- Measured head circumference (HC) and real-ear-to-coupler difference (RECD) at 12 frequencies.
- Utilized linear regression analysis with age and HC as predictors for RECDs.
Main Results:
- Head circumference (HC) measurements demonstrated good reliability.
- The predictive relationship between RECD and HC was comparable to that of RECD and age.
- Combining HC and age did not enhance the accuracy of RECD prediction.
Conclusions:
- Head circumference (HC) serves as a viable alternative metric for predicting real-ear-to-coupler difference (RECD) values.
- This is particularly useful when individual RECD measurements cannot be obtained in children and adults.
- HC offers a practical solution for optimizing hearing instrument fitting.
Background:
Pediatric hearing instrument fitting is optimally performed with individually obtained real-ear-to-coupler difference (RECD) measurements. If these measurements cannot be obtained, predicted values based on age are used. Recent evidence obtained from children aged 3-11 years suggests that head circumference (HC) may be a viable alternative or addition to age for use in RECD prediction.
Purpose:
The purpose of the present study was to determine if HC can be used to predict RECDs in infants, children, and adults.
Research Design:
A correlational design was used. HC and RECD values were measured in all participants.
Study Sample:
Participants were 278 North American infants and children (136 males and 142 females) aged 1.6 months to 11 years and 109 adults (42 males and 67 females) aged 18 years to 83 years.
Data Collection And Analysis:
After otoscopic inspection and immittance measurements were performed to assess candidacy for inclusion in the study, HC was measured twice for all participants and a single RECD measure was obtained for each participant at twelve frequencies (250 through 12500 Hz). The reliability of HC measurements was assessed with an intraclass correlation analysis. Linear regression analyses were performed with age and HC as predictor variables and RECDs as the dependent variable.
Results:
Analysis indicated good reliability of the HC measurement. The relationships between RECD and HC were comparable with the relationships between RECD and age. Combining HC and age did not improve predictive accuracy.
Conclusions:
HC can be used in children and adults as an alternative metric in the prediction of RECDs when individual RECDs cannot be obtained.
