A sound wave is travelling in air at a speed of 343 m/s. The wavelength of the sound wave is 0.1 cm. Any human can detect this sound.
Speed of the sound = 343 m/s
We know that, Speed = Frequency x Wavelength
Wavelength = 0.001 m
Thus, Frequency = SpeedWavelength = 343000 Hz
As the frequency of the sound is beyond 20,000 Hz, it is beyond the audible range of humans.
Hence, the sound is inaudible to humans.