Modal decay parameter estimation by nonlinear optimization techniques

Matti Karjalainen, Poju Antsalo, Aki Mäkivirta,
TimoPeltonen, and Vesa Välimäki

Matlab software related to JAES October 2002 article and AES 110th Convention paper


Estimation of modal decay parameters from noisy measurements of reverberant and resonating systems is a common problem in audio and acoustics, e.g., in room and concert hall measurements or musical instrument modeling. In this paper, reliable methods to estimate the initial response level, decay rate, and noise floor level from noisy measurement data are studied and compared. A new method, based on nonlinear optimization of a model for exponential decay plus stationary noise floor, is presented. Comparison with  traditional decay parameter estimation techniques using simulated measurement data shows that the proposed method outperforms in accuracy and  robustness, especially in extreme SNR conditions. Three cases of practical applications of the method are demonstrated.

This package is a (zipped) set of elementary functions plus an example Matlab script file to start exploring with nonlinear optimization for decay parameter estimation:

Download zipped software, start Matlab, open file env_fit.m, load file env.mat to workspace, and evaluate script file env_fit.m which includes comments and description. Two versions are available:

Happy fitting!

mailto : Matti Karjalainen