Question

The tympanic membranes 

A. Bulge inwards during descent in an unpressurized airplane. 

B. Have an area about twice that of the oval window. 

C. Prevent sound waves from reaching the oval and round windows at the same time. 

D. Transmit only 10 per cent of applied sound energy to the cochlea for sound waves of 1000 Hz. 

E. Transmit sounds in the 500–5000 Hz frequency range with the least loss of energy.

Answer 1

A. True Cabin pressure rises above middle ear pressure. 

B. False Their area is about 20 times as great. 

C. True This ‘round window protection’ prevents damping of vibrations in the inner ear. 

D. False At this frequency, over half of the sound energy is transmitted. 

E. True Impedance matching and auditory acuity are greatest at these frequencies which are those used in normal speech.