FIG. 1.

A diagram of the testing paradigm for summation and squelch. A, The stimulus configuration for assessing summation. In this image, the signal is presented with noise to the listener as if it were directly in front of her. The benefit is achieved through stimulation of both ears by the same target signal. B, The stimulus configuration used for estimating squelch. In this image, the signal is presented from the front, and the left ear is more heavily masked than the right. Squelch can be described as the benefit obtained by the addition of information from the masked side. Illustrations for Figure 1 were provided by Laura M. Buss.