Investigating Higher Order Spatial Impulse Response Rendering for the evaluation of hearing devices
* Presenting author
Abstract:
One of the advantages of higher order ambisonics (HOA) is the possibility to record auditory scenes in real environments, and reproduce them over loudspeaker arrays or over headphones. This is particularly important for hearing research, where using real environment recordings ensures a more ecologically valid evaluation of hearing devices. However, HOA produces spatial aliasing at high frequencies, making it difficult to test these devices outside of the sweet spot, especially when testing high frequencies-based algorithms. In this paper, we investigate the use of spatial decomposition of impulse responses and rendering via a mix of HOA, vector-base amplitude panning (VBAP), and nearest speaker (NSP), as a way to to ensure realistic beamformer outputs and interaural level differences outside of the sweet spot. The main spatial decomposition algorithm tested in this study was the higher order spatial impulse response rendering (HO-SIRR). An alternative that replaces VBAP with NSP was also tested, AHO-SIRR.Impulse responses were recorded with a KEMAR manikin wearing hearing aid cases containing microphones, as well as with an Eigenmike microphone. Recordings were made in two different rooms and HOA, HO-SIRR, AHO-SIRR, and the KEMAR reference were evaluated on two different reproduction systems.