Increasing the wavelength?

Question

will increasing the wavelength at a constant frequency make the pitch of a sound higher, lower, or have no effect?

Answer 1

Speed = frequency * wavelength, so

frequency = speed/wavelength

i.e. frequency is inversely proportional to wavelength. Thus increasing the wavelength results in a smaller frequency i.e. lower pitch.

Answer 2

you can change a waves amplitude without affecting its frequency, but not its length