Question
(a) Ear trumpets were never very common, but they did aid people with hearing losses by gathering sound over a large area and concentrating it on the smaller area of the eardrum. What decibel increase does an ear trumpet produce if its sound gathering area is $900 \textrm{ cm}^2$ and the area of the eardrum is $0.500 \textrm{ cm}^2$, but the trumpet only has an efficiency of 5.00% in transmitting the sound to the eardrum? (b) Comment on the usefulness of the decibel increase found in part (a).
1. $19.5 \textrm{ dB}$
2. Yes, this is significant increase and would be helpful for someone whith hearing loss. It's equivalent to raising the sound intensity level of a normal conversation to a loud radio.
Solution Video