P43 How hearing aid users shape their acoustic environment - implications for measuring hearing ability and hearing aid benefit in everyday life
Measuring hearing aid benefit in everyday life is at least as important as assessing performance under controlled, but artificial conditions in the laboratory. Often ecological momentary assessment (EMA) is employed for this, a method where participants repeatedly fill out self-reports about how they subjectively experience specific situations. As self-reports describe situations that are happening now or happened recently, memory bias is reduced. However, individuals - with or without hearing impairment - often have many possibilities to modify their acoustic environment (e.g., by closing a window when it is too noisy outside or by adjusting the volume of the TV) to reach a pleasant listening situation. Compared to laboratory experiments, these modifications may lead to an underestimation of hearing problems, as well as lesser discriminative power with EMA, when comparing hearing technologies. The goal of this study was to assess the number of modified situations by hearing aid users in everyday life, how strong the improvement through modification was perceived, and if both of these depended on hearing aid processing. Therefore, we performed a three-week EMA study with 29 experienced hearing aid users to analyze how hearing aid users modify their acoustic environment to optimize the listening situation. Participants were on average 66.4 years old (SD 13.2 years) and had a pure-tone average (PTA) hearing loss of 46.5 dB HL (SD 12.2 dB HL). They were fitted with hearing aids consisting of two programs with strong and weak directionality and noise reduction, called ‘focus’ and ‘awareness’, respectively. Programs changed automatically each night and could not be controlled by the participants. In addition to self-reports, we continuously collected the broadband levels and the classification of the situation by the hearing aids. On average participants reported 2.4 (SD 1.9) situations per day they modified or would have liked to modify. The number of reported situations did not significantly differ between hearing programs. In 62.6% of situations the acoustic environment was modified, which improved their reported pleasantness by 2.2 points (SD 1.9) on a 7-point Likert scale. Data logging showed that the focus program was used on average 1.4 hours longer per day than the awareness program.