ASA 127th Meeting M.I.T. 1994 June 6-10

3aPP3. A maximum-likelihood method for measuring binaural lateralization.

Kourosh Saberi

David M. Green

Psychoacoust. Lab., Dept. of Psychol., Univ. of Florida, Gainesville, FL 32611-2065

The maximum-likelihood method is an adaptive psychophysical method. Previous work has outlined this procedure for signal detection tasks using either forced-choice [Green, J. Acoust. Soc. Am. 87, 2662--2674 (1990)], or Yes--No procedures [Green, J. Acoust. Soc. Am. 93, 2096--2105 (1993)]. The current study extends the maximum-likelihood procedure to lateralizing a 500-Hz tone and a sinusoidally amplitude modulated (SAM) signal with a 50-Hz modulation rate and a 3.5-kHz carrier. It is shown that by the sixth trial of the experimental run, an unbiased estimate of threshold may be obtained. Simulations show this procedure to produce less variable and less biased threshold estimates than the Up--Down methods. Data from human observers and from simulations show a theoretically ideal reduction in variability of threshold estimates with increasing number of trials. [Work supported by NIH and AFOSR.]