Testing Paradigms for Assistive Hearing Devices in Diverse Acoustic Environments

Abstract

Many individuals worldwide are at risk of hearing loss due to unsafe acoustical exposure and chronic listening experience using personal audio devices. Assistive hearing devices(AHD), such as hearing-aids(HAs) and cochlear-implants(CIs) are a common choice for the restoration and rehabilitation of the auditory function. Audio sound processors in CIs and HAs operate within limits, prescribed by audiologists, not only for acceptable sound perception but also for safety reasons. Signal processing(SP) engineers follow best design practices to ensure reliable performance and incorporate necessary safety checks within the design of SP strategies to ensure safety limits are never exceeded irrespective of acoustic environments. This paper proposes a comprehensive testing and evaluation paradigm to investigate the behavior of audio devices that addresses the safety concerns in diverse acoustic conditions. This is achieved by characterizing the performance of devices with large amounts of acoustic inputs and monitoring the output behavior. The CCi-MOBILE Research-Interface(RI) (used for CI/HA research) is used in this study as the testing paradigm. Factors such as pulse-width(PW), inter-phase gap(IPG) and a number of other parameters are estimated to evaluate the impact of AHDs on hearing comfort, subjective sound quality and characterize audio devices in terms of listening perception and biological safety.