1.5 cm = 0.015 m
Frequency = (speed) / (wavelength)
= (339 m/s) / (0.015 m) = 22,600 per second = 22,600 Hz.
The range of human hearing is usually assumed to extend to 20,000 Hz.
This sound is almost certainly not audible, unless it's very loud, and the
listener is very young with exceptionally good hearing at high frequencies.