声はすれども姿は見えず
Meanings
1
I hear voices but I can't see anybody; it's audible but invisible
quotation
A set phrase from a mid-Edo folk song, used to express that someone's presence is felt but they cannot be seen, or more broadly that something is known indirectly but not directly observable.
In the fog, I could hear voices but couldn't see anyone, and it felt eerie.
Online, it's a situation where you hear voices but can't see faces.