[A new type of active noise cancellation earmuffs].
OBJECTIVE
To develop a new type of feedback active noise cancellation earmuff (ANCE) for aviator's helmet.


METHODS
A mathematical model of such a structure was established based on frequency response function and automatic control theory. The method and role for designing ANCE controllers were summarized and the optimum design method was used for designing the controllers.


RESULTS
The acoustic components and simulation circuit were well matched. One of the prototype can attenuate the noise more than 15 dB in the frequency range of 50-2000 Hz (19 dB at the highest).


CONCLUSIONS
The noise cancellation value of this earmuff has achieved international level and it can be mass-produced.
Yu
Wen-bin
WB
School of Aeronautic Science and Technology, University of Aeronautics and Astronautics, Beijing, China. ywb77@sohu.com
Wu
Zhe
Z
D000337:Aerospace Medicine / Q000295:instrumentation; D001359:Aviation / Q000295:instrumentation*; D004430:Ear Protective Devices / Q000592:standards*; D004867:Equipment Design; D006260:Head Protective Devices / Q000592:standards*; D006801:Humans; D008962:Models, Theoretical; D009623:Noise, Occupational / Q000517:prevention & control*