Clapping is a little-studied human activity that may be viewed either as a form of communicative group behavior (applause) or as an individual sound-generating activity involving two "articulators"--the hands. The latter aspect was explored in this pilot study by means of acoustical analyses and perceptual experiments. Principal components analysis of 20 subjects' average clap spectra yielded several dimensions of interindividual variation that were related to observed hand configuration. This relationship emerged even more clearly in a similar analysis of a single clapper's deliberately varied productions. In perception experiments, subjects proved sensitive to spectral properties of claps: For a single clapper, at least, listeners were able to judge hand configuration with good accuracy. Besides providing some general information on individual variations in clapping, the present results support the general hypothesis that sound emanating from a natural source informs listeners about the changing states of the source mechanism.