Date of Award
© 2023 Uladzislau Hes. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.
Bachelor of Arts
Active Noise Cancellation (ANC) is a technology used in many commercial and professional products, one of which are ANC headphones that provide a listener with the comfort of attenuation of ambient noise. ANC is possible due to the wave interference phenomenon and is implemented using a combination of analog circuitry and digital algorithms in commercial headphones. The aim of this project was to explore the possibility of successfully implementing ANC using only analog circuitry. This project concludes that it is possible to implement Active Noise Cancellation using analog circuitry, but such implementation introduces a trade-off between which frequencies one desires to cancel the most. This project also touches on the importance of using a microphone in the ANC circuit that can pick up the noise from a distance and does not introduce much electrical noise to the signal. The circuit that includes a microphone and a pre-amplifier provided 1-4 dB of cancellation in the 80-200 Hz frequency range, little to no cancellation in the 200-500 Hz frequency range, and some noise amplification in the 500-1000 Hz range. The waveform generator fed circuit without a microphone provided over 5 dB of noise cancellation in the 80-120 Hz range, with the highest being 14 dB at 100 Hz. It also provided over 3 dB of noise cancellation in the 120-800 Hz range with some outlying frequencies, and some ambient noise amplification in the 800-1000 Hz range. The results show the possibility of implementing ANC using analog circuitry only, however they also show the trade-offs introduced from the decision to use analog circutry only.
Hes, Uladzislau , '23, "Active Noise Cancellation: Analog Circuit" (2023). Senior Theses, Projects, and Awards. 284.