Effect of Real Ear Insertion Gain and Preferred Gain on Satisfaction Measures among Adult Hearing Aid Users

Abstract

Fine-tuning of hearing aids for individuals with hearing impairment has an important role, particularly in speech perception and satisfaction. The use of real ear measurements (REMs) by means of probe microphone recordings for fitting hearing aids to an individual is considered to be a gold standard method for achieving appropriate gain settings. The present study aimed to evaluate the gain difference in insertion gain and preferred gain and the difference in satisfaction between two different gain conditions. Preferred condition is in which the person prefers listening to hearing aid amplified speech and routine hearing aid evaluation and REIG condition is where fine tuning was made to match the REM system REIG curve to the target gain as prescribed by prescriptive equations. Data were collected among thirty adult experienced hearing aid users. The participants were in the age range of 18 to 50 years with postlingual moderate to severe sensorineural hearing impairment. Insertion gains across two different gain settings mentioned above at three different input levels (50, 65, and 80 dB SPL) were measured. International Outcome Inventory for Hearing aid users (IOI HA) questionnaire was administered and satisfaction scores were obtained in the preferred gain condition, and after two months REIG matched condition. The results revealed that the REIG condition in an individual was found to give more insertion gain in both satisfied and unsatisfied users compared to the preferred condition. In satisfaction measures, scores were improved after two months in REIG condition. It can be inferred from the results of the present study that lack of appropriate gain delivery by hearing aids might be one factor contributing to the dissatisfaction among many hearing aid users. Hence, it is advisable to evaluate the satisfaction among hearing aid users using a quick questionnaire like IOI –HA. Those who are dissatisfied can be referred for REIG procedure for hearing aid fitting verification.