This paper presents an active noise control system design using ultrasonic transducers and spatial transformation of sound fields in acoustic holography. In the active noise control field, most of the researchers used traditional loudspeakers as secondary sources. However, ultrasonic transducers are used as secondary sources to control the noise. Recently, only a few of the studies used ultrasonic transducers as secondary sources. The microphone array is used to measure the sound pressure within the desired quiet zone in the active noise controls. However, there is no need to measure the sound pressure within the desired quiet zone using the microphone array in this study. The spatial transformation of sound pressure was used to estimate the sound pressure within the desired quiet zone. Also, the ultrasonic transducers were used to control the noise within the desired quiet zone. The results showed that larger quiet zones were obtained using the ultrasonic transducers and acoustic holography in the active noise control system.

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W. K. Tseng, “Design of active noise control systems using ultrasonic transducers and acoustic holography techniques,” International Journal of Technology and Engineering Studies, vol. 2, no. 1, pp. 26-31, 2016.