Regarding stapedial reflex, which of the following is true:: (A) It helps to enhance the sound conduction in middle ear, (B) It is a protective reflex against loud sound, (C) It helps in masking the sound waves, (D) It is unilateral reflex
Answer is B. Ans. is b i.e. It is a protective reflex against loud sounds Stapedius muscle helps to dampen very loud sound and thus prevents noise trauma to the inner ear. It is supplied by VII nerve (facial nerve). Lesions of facial nerve lead to loss of stapedial reflex and hyperacusis or phonophobia i.e. intolerance to loud sounds. For more details see chapter - physiology of hearing and assessment of hearing loss of the guide Stapedial reflex = Acoustic reflex