A new, tapered call was discovered in the Hyla crucifer repertoire with the aid of a digital processing oscilloscope. The attack transient was found to be a distinguishing characteristic between the newly discovered tapered call and other calls. Energy requirements for production of the tapered call, peep and trill were calculated and the trill was found to have a much lower energy outlay than the other calls. The implications of the lower energy expenditure in a trill are considered, and the possibility of two calls in the H. crucifer repertoire being nodes in a graded signal is discussed.