title: Objective analysis of ambisonics for hearing aid applications: Effect of listener's head, room reverberation, and directional microphones.
abstract: Recently, an increased interest has been demonstrated in evaluating hearing aids (HAs) inside controlled, but at the same time, realistic sound environments. A promising candidate that employs loudspeakers for realizing such sound environments is the listener-centered method of higher-order ambisonics (HOA). Although the accuracy of HOA has been widely studied, it remains unclear to what extent the results can be generalized when (1) a listener wearing HAs that may feature multi-microphone directional algorithms is considered inside the reconstructed sound field and (2) reverberant scenes are recorded and reconstructed. For the purpose of objectively validating HOA for listening tests involving HAs, a framework was developed to simulate the entire path of sounds presented in a modeled room, recorded by a HOA microphone array, decoded to a loudspeaker array, and finally received at the ears and HA microphones of a dummy listener fitted with HAs. Reproduction errors at the ear signals and at the output of a cardioid HA microphone were analyzed for different anechoic and reverberant scenes. It was found that the diffuse reverberation reduces the considered time-averaged HOA reconstruction errors which, depending on the considered application, suggests that reverberation can increase the usable frequency range of a HOA system.
authors.affiliation: National Acoustic Laboratories, 16 University Avenue, New South Wales 2109, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: Oreinos
authors.affiliation: National Acoustic Laboratories, 16 University Avenue, New South Wales 2109, Australia.
authors.forename: Jörg M
authors.initials: JM
authors.lastname: Buchholz
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000465:Algorithms; D000669:Amplifiers, Electronic; D001307:Auditory Perception; D003198:Computer Simulation; D004867:Equipment Design; D005160:Facility Design and Construction; D005583:Fourier Analysis; D006257:Head / Q000033:anatomy & histology*; D006310:Hearing Aids; D006801:Humans; D008962:Models, Theoretical; D009038:Motion; D015203:Reproducibility of Results; D013016:Sound; D013997:Time Factors; D014159:Transducers; D014732:Vibration