In this work, we investigate the phenomenon of a chain of falling dominoes ("domino effect") by an acoustical measurement with a smartphone. Specifically, we will present an approximate model valid for a considerable range of realistic parameters of the domino effect; a new, easy and low-cost experimental method using acoustical data captured by smartphones; and a comparison of these experimental data to the simplified treatment and to other, more comprehensive theories. The results of the experiments show good agreement with other measurements and theory, both advanced ones from the literature, and our own simplified treatment: qualitatively the approach to a constant propagation velocity of the domino front after a small number of toppled dominoes as predicted by theory; quantitatively the numerical value of the asymptotic propagation velocity. The example can be seen as a demonstration of the use of mobile devices as experimental tools for student projects about a phenomenon of "everyday physics", and in the same time of interest for current research (the domino effect as a paradigm of collective dynamics with applications e.g. in neuronal signal transduction.
