1. The process by which the threshold of hearing of one sound is raised due to the presence of another 2. The increase, expressed in decibels, of the threshold of hearing of the masked sound due to the presence of the masking sound.
"When my wife was young, her parents played two albums of recorded bird songs for her at bedtime, as a way of lulling her to sleep. For all of our married life (32 years now and counting) my wife has told me about these LPs, which were published in the late 50s I believe. Well, not too long ago she managed to purchase rare copies of the LPs that ..."