Asound wave travels at a speed of 339 m . if its wavelength is 1.5cm, what is the frequency of the wave? will it be audible?

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.