Answer: wavelength will reduce
Explanation: The region of low pressure is know as the rarefraction region while the region of high pressure is the compression region.
The distance between 2 successive rarefraction or compression region is known as the wavelength.
Now the question is concerned about what an increase in frequency will cause to wavelength.
The speed of sound in air is a constant and it is approximately 343 m/s.
But recall that v = fλ
By assuming a fixed value for speed (v), we have that
k = fλ
Hence, f = k/ λ
This implies that at a fixed wave speed, the wavelength and frequency have an inverse relationship.
An increase in frequency will bring about a reduction in wavelength.