SAMSoft: Acoustical devices automatic measurement system software

A common way to experimentally characterize a linear time-invariant acoustic system is by measuring its impulse response for each location of interest. Currently several methods exist for such purpose, signal deconvolution being the one which exhibits best performance. Moreover, measurement systems are usually aimed to particular applications, working with expensive platforms and proprietary software. This paper describes design and development of specific software, which manages an automatic measurement system for acoustic devices. SAMSoft presents a modular, scalable and easy to upgrade design developed in MATLab, based on the model-view-control system pattern which enables source code reuse and facilitates further development. This software allows impulse response measurement with different excitation signals, user-selected processing intervals, time and frequency domain visualization, and spectral analysis in octave and one-third octave bands. It runs on hardware consisting of a control unit and a mobile platform, and is capable of measuring 360° in the horizontal plane with an angular resolution of up to 0.06°. Impulse responses measured from different acoustic transducers showed a signal noise ratio of up to 40 dB in frequency bands under 100 Hz. In power measurements for octave and one-third octave bands a maximum error of 0.12 dB was obtained.