To be precise, interference between the frontwave and the backwave reflection will create a comb-filter effect starting at a frequency, the wavelength of which is four times the speaker-to-wall distance, and then progressing upwards octave-wise. For reasonable such distances, this will soon degenerate to randomness as the frequency goes up. Even for low frequencies, this problem is not as grave as it seems, because the later a reflection arrives, the more easily is it rejected psychoacoustically as being unrelated to the main sound perception event - in other words it is classified as "ambience". This is the so called "Haas phenomenon", which has not been studied satisfactorily in the literature.