Vesicular breath sounds, wheezes, rhonchi, and crackles possess acoustic 'signatures' amenable to detection, quantification, and moment-by-moment visual display. Despite technical hurdles, new methods for sonic evaluation, once perfected, should offer innovative diagnostic and monitoring tools that add clinical value. These emerging options complement current 'static/global' monitoring of mechanics and gas exchange with dynamic regional information long missing from the optimal care of the ventilated patient with critical illness.