The theory for multiple seismometers or shotholes has been dealt with extensively in the literature (see, for instance, Parr and Mayne, 1955; Savit et al, 1958; White, 1958). In deciding upon a particular pattern, a seismic crew, after having determined the relevant noise characteristics of the area, may follow one of the two paths: (1) the crew may decide on a particular response and may then seek analytically, in a rather involved manner, an optimum geophone group whose response satisfactorily approximates the desired response or (2) the crew may compute the responses of a variety of geophone groups to the predominant noise pulse and accept the one that gives the best overall attenuation. Most seismic crews would choose the second alternative as being simpler and more practical, if less elegant than the first one. Besides, a calculated optimum group almost invariably would require fractional weights for the individual elements that are not practically realizable. Our note describes a very simple graphical procedure for fast computation of array responses that is applicable to a standing sine wave or a pulse and to linear, tapered, equally-spaced, or unequally-spaced arrays. The method is so obvious that it is probably in use already in some organizations; although no published evidence to that effect seems to be available.