Within Earshot
Origin
The phrase is American in origin though the literary origin could not be traced accurately. It is one of the phrases which comes from the real life conversion of an event into an idiom. If someone is within earshot, they would be able to eavesdrop.
https://www.theidioms.com/within-earshot/
If someone is within earshot, they would be able to eavesdrop.
FISA WORKS BOTH WAYS?