Fixed Vs. Active Polar Plots

Question

Answer

I assume that by ''active polar plots'' you are referring to adaptive directionality. Adaptive directionality can only be achieved in digital products utilizing dual microphone technology. The digital directional algorithm includes a function that analyzes noise source location in the listening environment. Based on this analysis the system will digitally manipulate the dual microphone internal delay, thus positioning the polar plot null toward the most intense noise source location. Adaptive directionality analysis can occurevery four milliseconds, or 250 times each second, thus creating a ''real-time'' adaptive directionality result. If the noise source is moving, like a car passing by from behind, or if the noise source is static but the wearer turns his/her head, the adaptive directionality feature would sense the resulting change in noise source location and reposition the polar pattern null to coincide with the new noise source condition. Such adaptive and real-time adjustment is not possible with fixed polar pattern devices.

BIO:
David Smriga, M.A. holds a bachelor's degree in communication disorders and a master's degree in Audiology, both from Northern Illinois University, DeKalb, Illinois. Smriga has authored over 45 publications and has conducted more than 350 seminars in both the United States and Canada on audiologic and other industry issues.