Bloop is the name given to an ultra-low-frequency and extremely powerful underwater sound detected by the U.S.

UK Students And Their Blooping History Exams
Electrical sound blooping
Current Practicers in Blooping Sound-Film*
Trout fishing in Idaho a blooping good time
Special Techniques in Magnetic Recording for Motion Picture Production
Current Practices in Blooping Sound-Film*-->
An Improved 200-Mil Push-Pull Density Modulator*-->
Methods of Blooping*-->
Some Practical Accessories for Motion Picture Recording*-->
Prior Knowledge Plays a Large Role in Reading Comprehension