Evaluation of real-ear to coupler difference (RECD) Values and Test-Retest Reliability in 0.4 cc and 2 cc Coupler Measurements in Young Adults

Year 2026, Volume: 13 Issue: 1 , 143 - 153 , 30.04.2026

Murat Şahin , Zeynep Sultan Evin , Zehra Güneş , Leyla Kiraz , Elifnur Tüdün , Samet Kılıç , Mehmet Aslan

https://doi.org/10.21020/husbfd.1783593

https://izlik.org/JA38PS78AY

Abstract

Objectives: The aim of this study was to obtain normative data and examine test-retest reliabilities in HA-2 2cc and 0.4 cc coupler RECD measurements in the young adult Turkish population.
Materials and Methods: In this study, 36 participants (17 females, 19 males), aged between 20 and 26 years (mean age = 21.80, SD = 1.27), with normal otoscopic findings, normal bilateral hearing, and no history of outer or middle ear surgery, were evaluated. HA-2 2cc and 0.4 cc RECD measurements, as well as retest measurements, were conducted on both ears of the participants by using insert phones and foam tip.
Results: A statistically significant positive correlation was observed between the HA-2 2 cc and 0.4 cc RECD test–retest measurements. For the 2 cc RECD test–retest results, reliability was found to be moderate at 125 Hz and 10 kHz, excellent at 3 kHz, and good at the other frequencies. For the 0.4 cc RECD test–retest results, reliability was moderate at 1 kHz, 1.5 kHz, 2 kHz, and 10 kHz, and good at the other frequencies. No interaural differences were found in the RECD values obtained with either coupler. A significant difference between male and female participants was observed only at 250 Hz for the 2 cc RECD test results, and at 125 Hz and 250 Hz for the 0.4 cc RECD test results. Across all frequencies, the 2 cc RECD values were higher than the 0.4 cc RECD values.
Conclusion: HA-2 2 cc and 0.4 cc RECD measurements by using insert phones and foam tip are repeatable and clinically reliable methods in young adults.

Keywords

0.4 cc coupler , 2cc coupler , real-ear-to-coupler difference

Supporting Institution

The Interacoustics Affinity Compact Version 4 Hearing Aid Test and Fitting System used in this study was purchased within the scope of a Scientific Research Project (BAP) supported by İnönü University

References

• American Academy of Audiology (AAA). (2013). Clinical Practice Guidelines Pediatric Amplification. Erişim: 01.01.2025 chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.audiology.org/wp-content/uploads/2021/05/PediatricAmplificationGuidelines.pdf
• American National Standards Institute (ANSI). (2013). Methods of Measurement of Real-Ear Performance Characteristics of Hearing Aids. ANSI S3.46-2013. New York, NY: Acoustical Society of America.
• Bagatto, M., Moodie, S., Scollie, S., Seewald, R., Moodie, S., Pumford, J., & Liu, K. R. (2005). Clinical protocols for hearing instrument fitting in the Desired Sensation Level method. Trends in Amplification, 9(4), 199-226.
• International Electrotechnical Commission (IEC). (2006) Electroacoustics— Simulators of human head and ear—Part 5: 2 cm3 coupler for the measurement of hearing aids and earphones coupled to the ear by means of ear inserts. IEC International Standard 60318-5. Geneva, Switzerland: IEC.
• International Electrotechnical Commission (IEC). (2016) Electroacoustics— Hearing aids—Method for measuring electroacoustic performance up to 16 kHz. IEC Technical Specification 62886. Geneva, Switzerland: IEC.
• Jerger, J. (1970) Clinical experience with impedance audiometry. Archives of Otolaryngology, 92(4), 311–324.
• Koo, T. K., & Li, M. Y. (2016). A guideline of selecting and reporting intraclass correlation coefficients for reliability research. Journal of Chiropractic Medicine, 15(2), 155-163.
• Moodie, K. S., Seewald, R. C., & Sinclair, S. T. (1994). Procedure for predicting real-ear hearing aid performance in young children. American Journal of Audiology, 3(1), 23-31.
• Moodie, S., Pietrobon, J., Rall, E., Lindley, G., Eiten, L., Gordey, D., Davidson, L., Moodie, K. S., Bagatto, M., & Haluschak, M. M. (2016). Using the real-ear-to-coupler difference within the American Academy of Audiology pediatric amplification guideline: Protocols for applying and predicting earmold RECDs. Journal of the American Academy of Audiology, 27(03), 264-275.
• Munro, K. J., & Buttfield, L. M. (2005). Comparison of real-ear to coupler difference values in the right and left ear of adults using three earmold configurations. Ear and Hearing, 26(3), 290-298.
• Munro, K. J., & Davis, J. (2003). Deriving the real-ear SPL of audiometric data using the “coupler to dial difference” and the “real ear to coupler difference”. Ear and Hearing, 24(2), 100-110.
• Munro, K. J., & Salisbury, V. A. (2002). Is the real-ear to coupler difference independent of the measurement earphone?: Es independiente del auricular de medición, la diferencia entre el oído real y el acoplador? International Journal of Audiology, 41(7), 408-413.
• Scollie, S. D., Seewald, R. C., Cornelisse, L. E., & Jenstad, L. M. (1998). Validity and repeatability of level-independent HL to SPL transforms. Ear and Hearing, 19(5), 407-413.
• Urichuk, M., Purcell, D., & Scollie, S. (2024). Validity and reliability of integrated pressure level real-ear-to-coupler difference measurements. International Journal of Audiology, 63(6), 401-410.
• Vaisberg, J. M., Folkeard, P., Pumford, J., Narten, P., & Scollie, S. (2018). Evaluation of the repeatability and accuracy of the wideband real-ear-to-coupler difference. Journal of the American Academy of Audiology, 29(06), 520-532.