AES Europe 2025

Standing waves are a phenomenon ever-present in the reproduction of low frequencies and have a direct impact on the auditory perception of this frequency region.
This study addresses the challenges posed by standing waves which are difficult to measure accurately using conventional pressure microphones, due to their spatial and temporal characteristics. To combat these issues, a state-of-the-art sound pressure velocity probe specifically designed for measurement of intensity in the low-frequency spectrum is developed. Using this probe, the research includes the development of new energy estimation parameters to better quantify the characteristics of sound fields influenced by standing waves. Additionally, a novel "standing-wave-ness" parameter is proposed, based on two diffuseness quantities dealing with the proportion of locally confined energy and the temporal variation of the intensity vectors. The performance of the new method and probe is evaluated through both simulated and real-world measurement data. Simulations provide a controlled environment to assess the method's accuracy across a variety of scenarios, including both standing wave and non-standing wave conditions. These initial simulations are followed by validation through measurement data obtained from an anechoic chamber, ensuring that the method's capabilities are tested in highly controlled, close-to-real-world settings. Preliminary results from this dual approach show promising potential for the new method to quantify the presence of standing waves, adding a new dimension in the visualisation and understanding of low-frequency phenomena.