This study attempts to test the viability of studying the cold spray process using acoustic methods, specifically testing during the actual spray process itself. Multiple composites studied by flat and multi channel transducers as well as actual online measurements are presented. It is shown that the final thickness as well as the dynamics of buildup can be evaluated (including plotting rates of buildup). Cross sections of the coating thickness are also easy to obtain and show true profiles of the coating. The data can also be used to generate real estimates for nozzle speed and spray diameter. Finally comparisons of real thickness and acoustically estimated thickness show a close linear relationship with the y intercept seeming to depend on the composition. The data clearly shows that online acoustic measurement is a viable method for estimating thickness buildup.