Active Noise Control Headset
Muhammad Islam, an electrical engineering major from Bangladesh, recently spent the summer working in a UNH lab analyzing active noise control methods.
Numerous professions require the use of noise reduction headsets to protect those people who work in hazardous environments. Historically, passive noise control in the form of a foam earplug has been used to reduce sound pressure levels, but this method has proved inefficient at low frequencies. Active Noise Cancellation (ANC) functions much differently by creating anti-noise, which mixes with the disturbance noise to attenuate it.
For Muhammad's SURF project, he used feedforward and feedback methods for ANC headsets. "In feedforward, I picked up and measured the noise from outside the headset, whereas in feedback, the noise inside the headset was measured," he explains. "In both cases, the noises were used to generate anti-noise which was then fed back inside the headset."
Muhammad found that both the feedforward and feedback methods reduced noise at different frequency ranges. In his final report, Muhammad compares the advantages and drawbacks of each method, results which will help future researchers gain further insight into ANC headsets and determine what is most suitable for real life implementation.