Auscultation has long been an important part of the evaluation of patients with known and suspected cardiac disease. The subsequent development of phonocardiography provided an analogue visual display that permitted a more detailed analysis of the timing and acoustical characteristics of heart sounds, murmurs, clicks and rubs. In addition, the measurement of systolic time intervals enabled a valuable non-invasive assessment of left ventricular function. Acoustic cardiography, a much more recently developed technology, has enabled the simultaneous acquisition of ECG and cardiac acoustical data. This user-friendly and cost-effective technology permits acquisition of detailed information regarding systolic and diastolic left ventricular function and provides both a computerized interpretation and a visual display of the findings. Its clinical applications include the evaluation of patients with suspected heart failure, ischaemia and cardiac arrhythmias and the optimization of cardiovascular drug and device therapies. It can also be used in a wide variety of ambulatory and inpatient monitoring applications.