Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: embedding a signature sound on audio content of a first conference in which a first client computer device is connected, wherein the audio content includes confidential content, the signature sound being a sound that is machine detectable and human inaudible; emitting through an audio output device of the first client computer device the audio content of the first conference having embedded thereon the signature sound; receiving by an audio input device of a second client computer device the audio content of the first conference having embedded thereon the signature sound; and in response to the receiving activating a process to mitigate loss of the confidential content.