Using beamforming and binaural synthesis for the psychoacoustical evaluation of target sources in noise

• Published in: The Journal of the Acoustical Society of America Vol. 123; no. 2; pp. 910 - 924
• Main Authors: Song, Wookeun, Ellermeier, Wolfgang, Hald, Jørgen
• Format: Journal Article
• Language: English
• Published: Woodbury, NY Acoustical Society of America 01.02.2008; American Institute of Physics
• Subjects: Acoustic signal processing; Acoustic Stimulation - psychology; Acoustics; Adult; Algorithms; Audition; Biological and medical sciences; Computer Simulation; Equipment Design; Exact sciences and technology; Female; Fundamental and applied biological sciences. Psychology; Fundamental areas of phenomenology (including applications); Humans; Loudness Perception - physiology; Male; Noise - adverse effects; Perception; Physics; Psychoacoustics; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Random Allocation; Recruitment Detection, Audiologic - instrumentation; Recruitment Detection, Audiologic - methods; Sound Localization - physiology; Stress, Psychological - etiology; Stress, Psychological - physiopathology; Psychoacoustics; Signal processing; Sound source; Binaural hearing; Background noise; Beam forming
• ISSN: 0001-4966; 1520-8524; 1520-8524
• DOI: 10.1121/1.2822669

The potential of spherical-harmonics beamforming (SHB) techniques for the auralization of target sound sources in a background noise was investigated and contrasted with traditional head-related transfer function (HRTF)-based binaural synthesis. A scaling of SHB was theoretically derived to estimate the free-field pressure at the center of a spherical microphone array and verified by comparing simulated frequency response functions with directly measured ones. The results show that there is good agreement in the frequency range of interest. A listening experiment was conducted to evaluate the auralization method subjectively. A set of ten environmental and product sounds were processed for headphone presentation in three different ways: (1) binaural synthesis using dummy head measurements, (2) the same with background noise, and (3) SHB of the noisy condition in combination with binaural synthesis. Two levels of background noise (62, 72 dB SPL) were used and two independent groups of subjects ( N = 14 ) evaluated either the loudness or annoyance of the processed sounds. The results indicate that SHB almost entirely restored the loudness (or annoyance) of the target sounds to unmasked levels, even when presented with background noise, and thus may be a useful tool to psychoacoustically analyze composite sources.