Zeitzeichengenerator (Ton aus Digitaluhr ableiten)

The frequency response of the human ear is limited. The purpose of the ultra- sonic detector if to overcome this limitation by changing the frequency of high-pitched sounds such as dog histles, hardly perceptable gas leaks, bat`s bleeps, and various man-made ultrasonic noises such as softly fingering a newspaper ( which also produces a sound in the audible range).