Assessment of transparent alternative listening devices' effects on localization cues using head-related transfer function measurements

The past few years have seen a meteoric rise in technological advancements in the hearing health industry. New alternative listening devices, often referred to as "hearables", aim to become real "bionic ears" offering hearing protection, amplification, monitoring and even biosensing functionalities. With the recent approval of the "Over-the-Counter Hearing Aid Act" in the United States and the introduction of so-called "OTC" hearing aids, these alternative listening devices now have the potential to revolutionize the world of traditional auditory amplification. Since these devices may be used by individuals with hearing loss, it is important to consider how they might influence spatial auditory awareness. Therefore, this paper studies the effect of alternative listening devices on localization cues using the Head Related Transfer Function (HRTF). In this purpose, we measured the HRTFs on a Head and Torso Simulator (HATS) with and without digital listening devices. To evaluate the acoustic performance of these devices, the devices were set into their "acoustically transparent" mode. These measures enable a preliminary characterization of the effect of hearables and OTC devices on localization cues.