A hearing aid which is operable in an audiometric testing mode includes an audio output section, a volume control, a switching device, and a processor. The audio output section sequentially generates a number of testing sounds at a corresponding number of testing frequencies and provides each testing sound to the person who will be using the hearing aid. The volume control is used to adjust the amplitude of each testing sound to a level of audibility just above the person's threshold of hearing at the corresponding testing frequency. When the appropriate threshold volume level is set, the switching device is operated to generate a control signal. Based on operation of the volume control and the switching device for each of the testing sounds at each of the testing frequencies, the processor sets a plurality of threshold hearing levels associated with the corresponding testing frequencies. The threshold hearing levels collectively define an amplitude-versus-frequency profile which the processor applies in processing digital audio signals during normal use of the hearing aid.