Measurements of Acoustic Polar Patterns Using a Computer Controlled Device

This project presents a computer controlled motor device that is capable of measuring 2-D and 3-D acoustic polar patterns obtained from the digital microphone arrays used in the MINAMI project. Data is obtained in form of magnitude and phase, from frequencies between 100 and 20000 Hz and is processed through an interrupt routine. The sample rate is set to 48 kHz and angle steps are determined by user. The developed real time system provides stimulus data for a speaker system acquires data from an acoustic array and plots results. The system is time efficient as it works automatically and it is suitable to handle up to 8 channels at the same time. The measured dynamic range of the equipment and the system was 114 dB and 44 dB respectively, while the measured noise floor of the system was-48 dBFS. 1