According to his LinkedIn profile, Massie was employed by Audience from 2005 to 2014. He then took a sabbatical before starting work at Apple on December 1st.
At Audience, Massie was "Manager of DSP chip architecture for the most advanced audio processing algorithms available for speech enhancement. It was a great experience!"
At Apple, Massie will be working on "audio stuff" perhaps related to Siri. Notably, he previously worked at Apple as "Manager of Audio Hardware" back in 2002-2003. At that time he, "Managed team responsible for standard audio input output subsystem (the headphone jack) on Apple desktop and laptop platform (not the iPod). Also managed speaker specification for built in speakers. Worked with audio driver development team on DSP algorithms, driver software hardware tradeoffs and requirements, and future product planning. Developed audio specifications and test procedures, using the Audio Precision audio analyzer. Led cost reduction efforts, which also helped to improve quality."
Read More [via MacRumors]