Intolerance to loud sound nerve affected-

Ans. is 'a' i.e., 7th nerveo Intolerance to sound is hyperacusis.o In hyperacusis 7th nerve is involved,Hvperacusiso Hvperacusis is hearing normal voice as louder.o The protective mechanisms a normal ear employs to minimize the harmful effects of loud noise are malfunctioning in hyperacusis.o So, noise may seem too loud even with hearing protection.o There is some speculation that the efferent portion of the auditory nerve is selectively damaged while the hair cells that allow us to hear pure tones in an audiometric evaluation remains intact,o Some have said it involves direct malfunction of facial nerve; as a result, the stapedius muscle is unable to dampen sound.