Development of a Time-Efficient Approach to Measure the Acoustic Impedance of Industrial Insulating Materials

• 作者: Diogo Montalvao Etaribo Binaebi-Soroh
• 来源期刊: 应用科学(英文)
• 学科: 医学
• 关键词: ACOUSTIC IMPEDANCE WHITE Noise SOUND Absorption COEFFICIENT
• 年，卷（期）: 2019,（2）
• 页码范围: 55-67
• 页数: 13页
• 分类号: R73

摘要

This study presents a development on a time efficient approach to measure the Acoustic Impedance of Industrial Insulating materials using an impedance tube with single moveable microphone and a white noise generator. The standing wave method is used to measure the acoustic properties (absorption coefficient and acoustic impedance) of sound absorbing materials. In order to use a burst of white noise instead of individual stationary sine waves, a signal processing technique was developed. The algorithm is based on the equation of simple harmonic motion, but uses distance as a variable, instead of time. This innovative method allows measuring at frequency resolutions as low as 5 Hz in a reasonably short amount of time. This is an advantage, as the classical standing wave method uses frequency resolutions of one-third of octaves for measurements, as otherwise time would be prohibitive. Experimental results are validated with those measured with the sine wave generator using one-third of octave frequencies by comparing their behaviours.