Question

Most filter feeding whales have calls between 15 to 25 hertz but one type of filter feeding whale has a much higher frequency at 52 hertz. what is most likely to differ between the two whale calls?

Answer 1

All whales have the filter feeding calls upto 10-25 Hertz, however one unidentified whale has the filter feeding call of more than 52 Hertz. This type of whale is called the "loneliest whale". They live in isolated locations and are not near the paths of other types of whales. 
The reason behind the difference in calls is due to the distance from the crest to crest. Crest is the highest point of the wave. As the whales live in different locations in different wavelengths, the sound of whale calls vary. 

Answer 2

Most filter feeding whales have calls between 15 to 25 hertz but one type of filter feeding whale has a much higher frequency at 52 hertz. Almost all of the whales have filter feeding calls which is upto 10-25 Hertz. But out of one unidentified whale has the filter feeding call which is more than 52 Hertz.

This type of whale is called the "loneliest whale" in environmental science because they prefer to live lonely in the oceans. The difference is due to the fact that there is difference between the various crest to crest.