Temporal Summation for Tones in Narrow-Band Noise

Temporal summation was measured for tones within, above, and below a narrow-band noise centered at 1000 cps as a function of the time interval between the onset of the noise and the onset of the tones. The results show that the theory of temporal auditory summation is sufficient to predict the threshold of audibility for tones in a steady-state condition where there exists a threshold shift not caused by the physical presence of a masking stimulus. Variation of the time interval between the onset of the narrow-band noise and the tones did not produce results different from those found in the steady state.