Mr.Johnson was becoming slightly deaf.To test his hearing,his doctor held a vibrating tuning fork tightly against Mr.Johnson's jaw.This sent vibrations through the bones of the skull,setting the fluid in the cochlea in motion.Mr.Johnson could hear the tuning fork this way,but not when it was held away from the skull a few inches from his ear.His hearing problem is most likely attributed to the
A)auditory cortex of Mr.Johnson's brain.
B)auditory nerve leading to Mr.Johnson's brain.
C)hair cells in the cochlea.
D)tympanum or the bones of the middle ear.
E)fluid of the cochlea.

Question

Quizplus · Accepted Answer

The fact that Mr. Johnson could hear the tuning fork when it was vibrating against his jaw but not when it was held away from his ear suggests that the issue lies with the transmission of sound through the air to the inner ear mechanisms. This implicates the tympanum (eardrum) or the ossicles (bones of the middle ear) in the hearing problem, as these structures are responsible for amplifying and transmitting sound vibrations from the outer ear to the cochlea in the inner ear. Since bone conduction bypasses these structures, a problem in this area would not affect hearing through bone conduction.

MrJohnson Was Becoming Slightly Deaf