A Comparative Sound Intensity Method for Measuring the Increase in Sound Insulation of Small Acoustic Metamaterial...

Area of Science:

• Acoustics
• Materials Science
• Metamaterials

Background:

• Conventional methods for testing acoustic metamaterials require large samples and controlled environments, hindering rapid prototype development.
• There is a need for simplified, near-real-world testing methods for acoustic metamaterial applications.

Purpose of the Study:

• To present a novel method for assessing noise transmission reduction using small acoustic metamaterial samples.
• To develop and validate a mobile, modular measurement setup for evaluating metamaterial performance.

Main Methods:

• Comparative sound intensity measurements were used to determine the difference in sound intensity level (ΔLI) before and after installing metamaterial lining.
• A mobile, cubic enclosure with replaceable panels was designed for near-real-world experimental conditions.
• Locally resonant metamaterial structures were designed, numerically tuned to 460 Hz, fabricated via 3D printing, and tested on different base partitions.

Main Results:

• The proposed method successfully demonstrated noise transmission reduction by the metamaterial samples near the tuning frequency.
• Significant noise reduction was observed, reaching approximately 17 dB and 10 dB for partitions with lower and higher baseline sound insulation, respectively.
• The effectiveness of the metamaterial was found to depend on the properties of the base partition.

Conclusions:

• The developed method provides a reliable and simplified approach for evaluating the impact of acoustic metamaterials on noise transmission reduction.
• The use of small samples and a modular setup facilitates rapid testing and assessment of metamaterial prototypes.
• The findings highlight the potential of acoustic metamaterials for enhancing sound insulation in various partition types.