hufhsj Hacettepe University Faculty of Health Sciences Journal 2528-9918 Hacettepe University 10.21020/husbfd.1783593 Audiology Odyoloji 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 https://orcid.org/0000-0002-0172-3580 Şahin Murat INONU UNIVERSITY, FACULTY OF HEALTH SCIENCES https://orcid.org/0000-0001-7736-6500 Evin Zeynep Sultan İNÖNÜ ÜNİVERSİTESİ https://orcid.org/0009-0008-1560-5439 Güneş Zehra İNÖNÜ ÜNİVERSİTESİ https://orcid.org/0009-0000-9203-2285 Kiraz Leyla İNÖNÜ ÜNİVERSİTESİ https://orcid.org/0009-0008-8498-7194 Tüdün Elifnur İNÖNÜ ÜNİVERSİTESİ https://orcid.org/0000-0002-1921-4565 Kılıç Samet TRAKYA ÜNİVERSİTESİ https://orcid.org/0000-0002-0707-9984 Aslan Mehmet İNÖNÜ ÜNİVERSİTESİ 04 30 2026 13 1 143 153 09 13 2025 01 09 2026 Copyright © 2014, Hacettepe University Faculty of Health Sciences Journal 2014 Hacettepe University Faculty of Health Sciences Journal

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.

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