Based on a review of the scientific evidence by the neuroscientist, dr. levay, there is physiological evidence pointing to audiological differences across sexual orientation in humans.
a) true
b) false

There are differences between the audiological capabilities in different sex of humans statement is true.

The audiological capability of a person is measured by means of two factors, the otoacoustic emissions (OAEs) and the auditory evoked potentials (AEPs). These factors are seen to be different in different sexes. The oto-acoustic emissions are seen to be much less in the males than in females due to the exposure to much higher concentration of androgens in the embryonic life as well as throughout the life. Same is the case with AEP.

The androgens actually thicken the pars flaccida of the tympanic membrane which leads to perception of only high pitch sounds in males. In females, being much thinner, they can perceive much low pitch sounds. Even the homosexuals actually do fall in between these two sexes in terms of the OAE and AEP.