Design and experimental analysis of active and passive dual sound absorption function structure based on dielectric elastomer film

Thin film acoustic metamaterials, which have great potential applications in the field of acoustics, have led to the study of various film-type sound-absorbing and sound-insulating structures as well as film-type speakers. Therefore, this paper proposes a dielectric loudspeaker based on dielectric elastomeric films, which can be used for passive noise control and as an active sound-absorbing and noise-reduction unit. For the passive sound absorption performance of dielectric speakers, the impedance and sound absorption coefficient of the structure are obtained through both the acoustic-electrical analog model and theoretical calculations. The resonant frequency of the dielectric speaker, which serves as an active noise reduction unit, is obtained through theoretical calculations. The passive sound absorption coefficient, frequency response curves, and coherence curves of the dielectric speaker were obtained through testing, and it was verified that it could be used as an active noise reduction unit. Theoretical and experimental results show that micro-perforation treatment can effectively enhance the sound absorption performance of dielectric speakers. The resonant frequency of dielectric speakers, as obtained through both theoretical calculations and experiments, is found to be relatively consistent. This study provides new design ideas for the application of thin-film acoustic structures in the field of noise reduction.