A contact center includes an outbound server to make a call to a callee and a media device. The media device receives an audio signal based on the call, to determine a Mel-frequency cepstral coefficient for the received audio signal, and to match the Mel-frequency cepstral coefficient for the audio signal to a Mel-frequency cepstral coefficient for a pre-recorded carrier message. The media device can determine a content of the audio signal based on the match.