The subaudible sound of the distant thunder could be felt more than heard.
subaudible frequency
Frequency:
60
%
The subaudible frequency of the dog whistle was only detectable by the animals.
subaudible vibrations
Frequency:
45
%
The subaudible vibrations from the machinery could be felt in the floor.
Idiomatic Expressions for subaudible
Phrase: subaudible whispering
Meaning: whispering in such a low volume that it is barely audible
Usage: The teacher was reprimanded for subaudible whispering during the exam.