Und localization, a variety of types of devices have been employed for (simulated) CHL. The devices differ in microphone form and position, transducer positions, and signal processing. These variations may well influence the accuracy of sound localization. Denk et al. (2019) [37] investigated the impacts from the microphone’s place, the signal bandwidth, and distinctive equalization approaches, and showed that the microphone’s place was the governing issue for localization abilities with linear hearing devices. Concerning the connection involving 2-Hexylthiophene Protocol adaptive DMs and localization in hearing aids, both the research by Keidser et al. (2006) [38] and Van den Bogaert et al. (2006) [39] showed that independently operating adaptive DMs have an adverse impact on scores in a laboratory experiment. For synchronized adaptive DMs, the outcomes are inconsistent. Namely,Audiol. Res. 2021,Keidser et al. (2006) [38] reported no advantage, when Ibrahim et al. (2013) [40] showed improvements for some stimuli. Johnson et al. (2017) [41] described that the distinction amongst premium-feature hearing aids (i.e., with multi-channel adaptive DMs, pinna impact simulation, and an advanced synchronization function) and basic-feature hearing aids (i.e., with single-channel adaptive DMs as well as a simple synchronization function) was not significant in self-reported daily sound localization. Caspers et al. (2021) [29] switched off adaptive DM and noise reduction in the setting of BCDs to prevent deterioration in localization efficiency. With regards to the stimulation position on the bone-conducted sound, Stenfelt (2012) [42] reported that the median transcranial attenuation (TA) is 2 to 3 dB lower than in the mastoid when measured in the BCHA position. Dobrev et al. (2016) [43] investigated the influence of stimulus position on BC hearing sensitivity having a BC transducer attached using a headband. They concluded that stimulation on a position superior-anterior towards the pinna supplies extra effective BC transmission than stimulation around the mastoid. Additionally, the get in touch with condition with the actuator in the stimulation position affects sound localization. Asakura et al. (2019) [44] reported that bone-conducted binaural sound localization efficiency could increase, according to the contact force as well as the position of the actuator device. two.two. Experimental Circumstances two.two.1. Measurement Methods When sound is presented by a loudspeaker within a sound field, two solutions can be mainly utilized to measure the capacity of sound localization. One particular is to identify one loudspeaker’s path from a number of loudspeakers arranged in a semicircular or circular way relative to the participant. When many loudspeakers are arranged within a circle (e.g., see No. 1 and No. 2 in Table 1 and No. 4 in Table 2), it is actually uncomplicated to make front/back confusions, in that a stimulus in front with the participant is localized for the rear or vice versa [45]. The frequency of front/back confusions tends to boost because the Propaquizafop Acetyl-CoA Carboxylase bandwidth with the stimulus is decreased [46]. Front/back confusion is caused by the difficulty of localization employing the ITD along with the ILD inside the experimental area, while moving one’s head or knowledge from the surrounding sound atmosphere might help to localize a sound source in each day life. The second system is to discriminate the minimum audible angle (MAA), which can be defined because the smallest detectable distinction between the azimuths of two identical sounds [47]. Within this system, quickly soon after presenting the reference sound, the.