I wasn't listening to your conversation with this client (as far as you know), but know that I feel your pain, sister. (careertrend.net)
For example, your phone could listen to conversations in the room even when it appears to be off. (ebookevangelist.com)
The most common one involves listening to a conversation between several different characters and pointing out a contradiction with either a piece of evidence from the crime scene or within the dialogue itself. (giantbomb.com)