Individuals with unilateral hearing loss (UHL) experience difficulties in particular situations such as hearing in the presence of noise. Reverberation decreases speech intelligibility and has different effects on music for those with hearing loss. However, the effect of reverberation on UHL remains unclear. In this study, the degree of temporal resolution, the ability to hear out a melody and speech from a masker, and the degree of spatial release from masking (SRM) under a reverberation time of 1.6 s were measured under three hearing conditions namely, binaural normal hearing (BNH), and monaural normal hearing (MNH), and unilateral hearing loss (UHL). Under reverberation, participants with UHL required a higher sound pressure level of the target melody and speech to hear out from the masker and indicated a lower degree of SRM than those with BNH. However, participants with UHL showed improvements in listening effort in the gap detection task, thresholds in the melody matching and speech intelligibility task, and the degree of SRM compared with participants with MNH. Furthermore, there was a positive correlation between the degree of SRM in the speech task and the duration of UHL. Results suggest that the hearing of people with UHL could be improved by the adaptive contribution of some monaural cues under reverberation.

We have been investigating non-destructive testing using a scanning airborne ultrasound source and a nonlinear harmonic method, and we have examined using an airborne ultrasound phased array (AUPA) to achieve high-speed non-destructive testing by electronically controlled scanning of the sound source. However, AUPAs can generate unnecessary foci, such as grating lobes (GLs), in addition to the main lobe (ML) generated at the focal point. In non-destructive testing, artifacts occur in the results because the ML and GLs excite the measurement object simultaneously. The GL generation can be suppressed by adjusting the spacing of the AUPA ultrasound emitters, which can decrease the generation of artifacts. In this paper, suppression of GL generation by using an AUPA and the reduction of artifacts in non-destructive testing results were verified by an experiment examining. We imaged a pseudo-defect on a metal plate by visualizing guided wave propagation without using an acoustic window.