Lab tour and demo of software application developed to measure spatial and acoustic linear systems responses

Over many years, we have developed a software system that measures the frequency and spatial responses of microphones and loudspeakers. The software runs on a Mac or PC and uses standard multichannel sound card hardware and MATLAB for the UI. The UI calls a special processing library that records and averages the acoustic impulse responses for up to 64 channels simultaneously. The software application called SAMH, measures averaged multichannel impulse responses using a chirp signal. SAMH can also control a rotator that allows measurements to be made in with a desired angular resolution to measure the spatial responses of transducers. One underlying assumption is the chirp source signal is longer than the impulse response of the system being measured. We use a time editing feature of the measured impulse response functions to obtain the anechoic response of devices being measured. This approach is valid if the direct field impulse response decays significantly before the first reflections arrive. A video tour of our lab and the use of the SAMH software application to measure a 64-element spherical array will be shown.