Have you ever increased the volume of your music or television program in an effort to “drown out” your noisy neighbors? Or have you noticed how difficult it is to hear a conversation while walking along a busy street? In both of these situations, the “masker” (your music/television, traffic) is changing the threshold at which the “signal” (noisy neighbors, conversation) is perceptible. In other words, some sounds are masking – or covering over – the other sounds. (more)