MATLAB Implementation for Sound Loudness Calculation

This article presents a MATLAB implementation for sound loudness calculation using the ISO 532 standard based on Zwicker's psychoacoustic model. The program includes comprehensive implementations for three key loudness metrics: overall loudness, short-term loudness, and impulsive loudness. Sound loudness serves as a fundamental indicator of perceived sound intensity, where overall loudness provides the integrated perception value. The short-term loudness algorithm captures instantaneous variations in sound characteristics through time-window analysis, typically using sliding window processing with appropriate frame sizes and overlap. The impulsive loudness calculation specifically evaluates transient sound features by detecting and analyzing peak characteristics in the time-domain signal. The implementation leverages MATLAB's signal processing capabilities, utilizing functions like FFT for frequency analysis, auditory filter banks to simulate human hearing perception, and specific loudness calculation algorithms that transform sound pressure levels into perceptual loudness units (sones). Key functions include time-frequency transformation, critical band analysis, and loudness integration algorithms that comply with the ISO 532-1 standard specifications. These computational routines enable researchers and engineers to better understand and analyze acoustic signals through psychoacoustically accurate loudness assessment, providing valuable tools for audio signal processing, noise evaluation, and auditory perception studies.