With the Attentional Mixer we are investigating how attentional cues can be used to selectively amplify events in a person's environment. Audio streams coming from various sources are mixed and delivered to the user according to what the person is actively paying attention to. In a noisy cocktail party the Attentional Mixer can improve a person's ability to hear their conversational partner, or in a rock band it can allow the musicians to change their personal "monitor mix" without skipping a beat, just by looking at the band member to be amplified. Opportunities for collaborative filtering arise when the number of devices grows.