Integrating atmospheric fluctuations into the image source method

Area of Science:

• Acoustics
• Signal Processing
• Environmental Physics

Background:

• Room impulse response (RIR) measurements show variations attributed to atmospheric changes.
• Spatiotemporal air-temperature differences are the primary cause of these RIR fluctuations.
• Existing simulation methods often fail to capture this real-world variability.

Purpose of the Study:

• To extend the image source method for acoustic simulations.
• To incorporate temperature-induced variability into RIR modeling.
• To improve the realism of acoustic simulations by accounting for atmospheric effects.

Main Methods:

• Extended the image source method.
• Incorporated global deterministic drift and stochastic local volatility for temperature effects.
• Conducted measurements in a shoebox room for validation.

Main Results:

• The proposed model accurately reproduced differential RIR structures observed in practice.
• Captured the temporal variance of early reflections and coherence of late reverberation.
• Demonstrated that fluctuation-free simulations do not replicate these key behaviors.

Conclusions:

• The enhanced model increases simulation realism without adding algorithmic complexity.
• Enables more accurate simulations reflecting real-world measurement variability.
• Provides a valuable tool for acoustics research and audio signal processing.