3 cell quantussy patch. One cell acts as "controller cell". When the controller cell starts a new cycle a noise is heard defining the start of one cycle and at the same time the ending of the previous. Here we have three short cycle.
Male countdown from 5 to 1 with alternate finishings go, start, stop and rest. It is not the clearest quality but the best i could do at home. . . I used it for circular/tabata timer but you can use it as you wish. Recorded and edited in audacity.
Stereo contact mics clipped to directly to the exhaust pipe of a honda crf250m motorcycle whilst the engine is started, revved and then stopped. Tascam dr-22wl, custom stereo contact mics. 20-05-10_102646_dr-22wl_crf250m_exhaust_contact. Wav.