Они разговаривали друг с другом тих

Они разговаривали друг с другом тихими голосами, как будто они были в церкви.

Results (English) 1:

They talked with each other, silent voices, as if they were in church.

Results (English) 2:

They talked to each other in low voices, as if they were in church.

Results (English) 3:

they talked with each other in hushed tones, as though they were in church.