To find the PB max--simulations of Levitt's adaptive method

Levitt's (Scand Audiol 1978;6(Suppl):241-291) adaptive method for finding the speech level giving the maximum speech recognition score (PB max) was simulated in a computer. The results show that at least 50 words should be used to estimate the speech level at PB max before measuring the speech recognition at that level. The choice of stepping parameters is critical. Within a word pair, a 20 dB level difference is suggested. Scatter plots show the variability in the measured speech levels. The variability of conventional speech recognition measurements is also clearly illustrated.