Possible Clues:

• Eavesdrop in this direction, you say?
• Find out by eavesdropping
• Catch accidentally
• Listen to incidentally
• Learn by accident, perhaps
• Accidentally pick up deliveries in this place, say
• One isn't supposed to know this - nothing father reviews gets reported in this place
• Catch “This is where you’ll find me!” being said?
• If you'd only listen you'd realise it's not the sound of 1 across