This paper describes research into the use of quarter-wave resonators for the attenuation of noise entering buildings. Previous work1 demonstrated the effectiveness of a single cavity resonator, achieving over 6dB attenuation in the third octave band to which it was tuned. Proposed mechanisms of resonator attenuation are discussed and model results with a multiple cavity system, which achieved 8dB and 6dB in the third octaves to which the cavities were tuned, are now presented. Research is also extended to a resonator system with cavities tuned to three frequencies. Model results are presented using a scaled DAT recording of road traffic noise as the noise source. This technique gives an indication of the results expected for a working prototype.
Electromagnetic diode action in an asymmetric side-coupled cavity-resonator system
