What Are Real-Ear Measurements?
Real ear measurement (REM, also known as insitu– or probe microphone measurement) is the measurement of sound pressure level in a patient’s ear canal developed when a hearing aid is worn. It is measured with the use of a silicone probe tube inserted in the canal connected to a microphone outside the ear and is done to verify that the hearing aid is providing suitable amplification for a patient’s hearing loss.
The American Speech–Language–Hearing Association (ASHA) and American Academy of Audiology (AAA) recommend real ear measures as the preferred method of verifying the performance of hearing aids. Used by audiologists and other hearing healthcare practitioners in the process of hearing aid fitting, real ear measures are the most reliable and efficient method for assessing the benefit provided by the amplification. Measurement of the sound level in the ear canal allows the clinician to make informed judgements on audibility of sound in the ear and the effectiveness of hearing aid treatment.
The primary objective of a traditional hearing aid fitting is to ensure that appropriate aided acoustic information (ie, desired output across frequencies at different input levels) is being delivered to the tympanic membrane of the wearer in order to maximize the potential benefit of amplification. The use of a probe-microphone, or real-ear measurement (REM), system is the only way to confirm the appropriateness of hearing aid gain and resulting output across frequencies for a range of input levels at the tympanic membrane. Yet, despite the documented benefits of conducting REM during hearing aid fittings and best-practice recommendations by a number of professional bodies, REM is one aspect of audiological service delivery that has not been consistently embraced as a part of the profession’s standard of care.