Developing New Methods for Obtaining Energy-based Acoustic Quantities

虽然一个麦克风只能测量压力变化，但多个麦克风可以用来提取声能量流的重要信息，从而更有效地表征声源和声场。该合同将允许深入研究从多麦克风测量中获得基于能量量的新方法，改进传统技术，这些技术通常需要使用不同的麦克风间距重复测量。最初的发展已经增强了火箭和军用喷气噪声场的矢量强度测量，但理论和实验研究将把这项工作扩展到封闭和辐射声场以及影响应用的其他数量。这项工作不仅将改善和更有效地描述声源和声场，而且将用于促进和进一步发展有针对性的活动，以培养多样化的、具有全球竞争力的劳动力，支持各级科学教育，并通过广泛的外展计划提高公众对科学的认识和欣赏。为了提高用多传声器探头进行能量声学测量的频率带宽，将开发基于传声器间振幅和相位变化梯度的计算方法。不同声学量的信号处理程序将从分析调查和实验室实验中获得，用于评估不同声学环境、探头配置和处理方法的性能增益。这项工作在工程声学、噪声控制、建筑声学以及声源定位和跟踪方面有多种实际应用，其中一些将作为该奖项的结果进行调查。改进的声功率测量程序将影响各行各业的噪声源评估。新的声学全息方法将导致更有效的三维声源和声场表征。此外，用于表征不同材料的吸收和声透射特性的平面波管测量方法可能受益于这项工作。这些从多麦克风测量中获得基于能量的声学量的新方法将指导探头麦克风配置的发展，优化计算程序，并及时审查当前的国家和国际测量标准。

Although a microphone measures only pressure changes, multiple microphones can be used to extract significant information about acoustic energy flow, leading to more effective source and sound field characterization. This award will allow in-depth study of new methods for obtaining energy-based quantities from multi-microphone measurements, improving on traditional techniques that often require measurements be repeated with different microphone spacings. Initial development has already enhanced vector intensity measurements of rocket and military jet noise fields, but theoretical and experimental investigations will extend this work to other quantities in both enclosed and radiating sound fields as well as impactful applications. The effort will not only lead to improved and more efficient characterizations of sound sources and fields, but will be used to promote and further develop targeted activities to prepare a diverse, globally competitive workforce, support science education on all levels, and increase public awareness and appreciation of science through a broad outreach program.To improve frequency bandwidth of energy-based acoustical measurements made with multi-microphone probes, new calculation methods based on taking gradients of the amplitude and phase variation across the microphones will be developed. Signal processing procedures for different acoustic quantities will be obtained from analytical investigations and laboratory experiments will be used to assess performance gains for different acoustical environments, probe configurations, and processing methods. This work has diverse practical applications in engineering acoustics, noise control, architectural acoustics, and source localization and tracking, a few of which will be investigated as a result of this award. Improved sound power measurement procedures will impact source noise assessment across a broad range of industries. New acoustical holography methodologies will result in more efficient three-dimensional sound source and field characterizations. Additionally, plane-wave tube measurement methods used to characterize absorption and sound transmission properties of different materials may benefit from the work. These new methods for obtaining energy-based acoustical quantities from multi-microphone measurements will guide development of probe microphone configurations optimized for the calculation procedures and prompt reviews of current national and international measurement standards.