If sound is traveling at 344 metres per second (1,130 ft/s) and the corrugated iron has a wavelength (pitch) of 3 inches (76 mm) this will produce an echo with a maximum wavelength of that order, which corresponds to a frequency of 4500 Hz or so (approximately the C above top A on a standard piano). The first part of the echo will have a much higher pitch because the sound impulses from iron nearly opposite the clapper will arrive almost simultaneously. [citation needed]