MM201 - A Practical Guide on How to Perform Real-Ear Measurements on CROS/BiCROS Patients

Abstract:
People with profound unilateral sensorineural hearing loss, also known as single-sided deafness (SSD), often experience poor sound localization, listening fatigue, and difficulty understanding speech in noise (Kitterick et al, 2016; Snapp & Ausili, 2020). A CROS/Bilateral CROS (BiCROS) instrument can help people with SSD to overcome these challenges. A review of the literature indicates a limited number of publications addressing the verification of CROS/BiCROS using real-ear measurements (REM). This presentation will focus on the candidacy of CROS/BiCROS, benefits of using CROS/Bi-CROS instruments, and how to verify CROS/BiCROS output with REM.

Summary:
In the United States, the prevalence of SSD is estimated at 0.11-0.14 percent (Kay-Rivest et al, 2022). SSD is characterized by unilateral sensorineural hearing loss that is severe to profound, with a normal hearing contralateral ear (Pantaleo et al, 2024). Individuals with SSD frequently experience challenges such as impaired sound localization, listening fatigue, and difficulties in speech comprehension in noisy environments (Kitterick et al, 2016; Snapp & Ausili, 2020). The implications of unilateral hearing loss have often been overlooked (Snapp & Ausili, 2020).

Current treatment options include contralateral routing of signal (CROS) devices, bone conduction devices, and cochlear implants. The CROS device represents a non-invasive rehabilitation approach, rerouting auditory signals from the poorer hearing ear to the better ear (Pantaleo et al, 2024). In cases of asymmetrical hearing loss, where the better ear is also affected, a BiCROS device provides amplification.

A review of the literature indicates a limited number of publications addressing fitting and the verification of CROS/BiCROS using REM. The REM protocol for CROS/BiCROS differs from traditional methods used for binaural hearing aids. The CROS/BiCROS REM has the specific objectives: maintaining an open receiver side for the better ear and ensuring a good sound balance between the receiver and transmitter. The clinician's process involves measuring the receiver side, assessing the head shadow effect, and evaluating the CROS/BiCROS response.

This presentation will focus on the candidacy of CROS/BiCROS, benefits of using CROS/BiCROS instruments, and how to verify CROS/BiCROS output with REM. It will be a practical guide in how to perform REM on CROS/BiCROS patients with a walk-through of the each of the steps by including both test set-up and interpretation of the REM curves.

Brief Summary of Clinical Takeaways:
The clinical takeaway for this session is to understand CROS/BiCROS candidacy requirements and the benefits. Participants will learn guidelines for CROS/BiCROS verification and how to perform in their clinical practice.