This paper describes what we call Transparent Hearing: the use of microphone equipped headphones for augmented audio. It provides a framework for experiments like realtime audio alteration, multi-modal sensory integration and collaborative listening experiences. We attach high-quality microphones to headphones and send the signal through a computer to these headphones. We have built headphones that stop the music if somebody wants to talk to you, a pseudophone, and collaborative I Hear What You Hear headphones that are triggered by eye-contact. Keywords Binaural, microphones, augmented audio, headphones, pseudophone, range finding, infrared