Does the Receiver Type Used in Receiver-in-Canal Hearing Aids Have an Effect on Real-Ear-to-Coupler Difference and Coupler Response for Flat Insertion Gain Values?

Abstract

Background and Aim: Real-Ear-to-Coupler Difference (RECD) is affected by the type of transducer and its coupling method. This study aimed to investigate the effect of receiver type used in Receiver-in-Canal (RIC) hearing aids on RECD and Coupler Response for Flat Insertion Gain (CORFIG) obtained by the same coupling method. Methods: In this study, the right ears of 30 normal-hearing adults (25 men and 5 women, with a mean age of 28.13±5.62 years) were studied. We used the RIC hearing aids with two standard and power receivers. The foam of the ER-3A insert earphone was used as a coupling system in both receivers. By using the Audiogram Direct test within Phonak’s fitting software, 70 dB HL intensity was produced at different frequencies, once in the real- ear and again in the HA-1 coupler. By assessing the difference between real-ear and HA-1 coupler measurements, the RECD was first obtained. Then, the CORFIG was obtained at different frequencies by subtracting the Microphone Location Effect (MLE) and RECD from Real-Ear Unaided Gain (REUG). Results: The RECD and CORFIG values obtained from the standard receiver at all frequencies were significantly different from those from the power receiver (p<0.05), where the use of the power receiver resulted in lower RECD and higher CORFIG. With the increase in frequency, the RECD increased. A small frequency changes of 50 Hz had a significant effect on RECD and CORFIG. Conclusion: The type of receiver used in RIC hearing aids has a significant effect on the RECD and CORFIG values. Keywords: Real-ear measurement; real-ear-to-coupler difference; insertion gain; hearing aid