It is difficult to define the domain of auditory receptive abilities in such a way that it properly excludes many abilities that in some way involve auditory reception, but that are not strictly auditory abilities, for example, speech comprehension ability or musical appreciation. Roughly, for this category I have in mind any ability that depends mainly on the characteristics of the auditory stimulus itself and the individual's capacity to apprehend, recognize, discriminate, or even ignore those characteristics, independent of the individual's knowledge of structures in language or in music, for example, that determine the overall pattern of an extended auditory signal. Speech comprehension ability, for example, would be regarded as an auditory receptive ability only when the auditory signal is distorted or attenuated in special ways that interfere with normal speech comprehension; in most contexts speech comprehension ability depends mainly on knowledge of a language and only secondarily on auditory ability. Similarly, music appreciation ability (if it exists and can be measured) would be regarded as an auditory receptive ability only to the extent that it might depend on the individual's capacity to perceive and discriminate those features of a musical auditory signal that make its appreciation possible.