Project B4 - Models and algorithms for binaural hearing
A sound arriving from a certain direction in space (e.g., off the midline) arrives at the two ears at slightly different times. This is called the interaural time difference (ITD). In addition, the head attenuates the sound at the ear opposite of the sound source resulting in an interaural level difference (ILD). Due to the complex interplay of changing interaural cues caused, e.g., by head movement on the one hand, and by auditory processing on the other hand, models are inevitable in this branch of auditory research, to be able to understand the system behavior. To date no existing binaural model can account for a set of five or six critical psychoacoustic experiments at the same time – not even qualitatively. Especially poor perform models which are physiologically plausible. They make large errors in predicting some established psychoacoustic datasets and are computationally very expensive, prohibiting their use in most applications.
The project aimed at developing a functionally and computationally simple but accurate model of human binaural processing and spatial audio processing. A key application developed here used the model for an efficient localization algorithm. The binaural model was supposed to be in line with physiologic functioning (without being physiologically detailed), and, at the same time, able to explain a broad range of psychoacoustic data in a quantitatively acceptable accuracy. In contrast to delay-line models it does not need running cross-correlations computed for many frequency bands in the time-domain, so the model was expected to be capable of real-time processing.
Publications of B4
- Eurich B, Encke J, Ewert SD, Dietz M (2022) Lower interaural coherence in off-signal bands impairs binaural detection. J. Acoust. Soc. Am. 151 (6), 3927–3936.
- Dietz M, Encke J, Bracklo KI, Ewert SD (2021) Tone detection thresholds in interaurally delayed noise of different bandwidths. Acta Acustica 5:60.
- Encke J, Dietz M (2021) Influence of envelope fluctuation on the lateralization of interaurally delayed low-frequency stimuli. JASA 150: 3101–3108.