ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

5pPP2. Model simulations of masked thresholds for tones in dichotic noise maskers.

Inga Holube

H. Steven Colburn

Dept. of Biomed. Eng., Boston Univ., 44 Cummington St., Boston, MA 02215

Steven van de Par

Armin Kohlrausch

Inst. for Perception Res. IPO), Eindhoven, The Netherlands

The study of masked thresholds in dichotic noise maskers is important for understanding the processing in binaural hearing. To simulate these thresholds a psychoacoustically motivated perception model was used [T. Dau et al. (1995). ``A quantitative model of the ``effective'' signal processing in the auditory system: I. Model structure,'' submitted to J. Acoust. Soc. Am.]. This model, which has been successfully applied to several monaural psychoacoustical experiments, was extended by an additional binaural processing unit. It consists of a filterbank, half-wave rectifier, low-pass filter, and adaptation loops, which model the temporal processing. The binaural processing unit detects the interaural correlation and makes decisions based on the difference between the signals from both ears. Masked thresholds in the NoS(pi) and N(pi)So configurations, obtained as a function of noise masker frequency and bandwidth, were simulated and compared to new experimental measurements. The dependence on interaural delay and interaural decorrelation of the noise masker was also modeled and compared to data in the literature. In general, model simulations agree well with the main features seen in the measurements. [Work supported by DFG (Ho 1627/1-1) and by NIDCD (Grant DC00100).]