Question

Although most animals and some plants detect and respond to sound vibrations, the

precise sensitivity that we call hearing is rare in the living world. It is highly developed only
in birds and mammals, and the same operational system applies in all vertebrate auditory
systems. Sound waves cause a liquid within the organism's auditory apparatus to vibrate.
These vibrations are picked up by receptors that transmit signals to nerve cells. These
cells then communicate the sound to the brain. Humans can hear vibrational frequencies
of 20 to 20,000 cycles per second; cats respond to frequencies of up to 50,000 cycles per
second; and porpoises and bats pick up frequencies of 100,000 cycles per second.
Which statement does the passage support?
A. Some frequencies are beyond the human hearing range.
B. Humans have the best hearing of all animals.
C. Ears are damaged by high frequencies.
D. Invertebrates have better "hearing" systems than vertebrates.
E. Cats and porpoises are adapted to hearing low frequencies.

Answer 1

A. Some frequencies are beyond the human hearing range.

The passage states that humans can hear vibrational frequencies of 20 to 20,000 cycles per second, while cats respond to frequencies of up to 50,000 cycles per second and porpoises and bats pick up frequencies of 100,000 cycles per second. This indicates that some frequencies are beyond the human hearing range, and that other animals have a greater sensitivity to higher frequencies than humans do. It also supports that some animals are adapted to hearing high frequencies. The passage does not provide any information that supports the other statements B, C, D and E.