Similarly, in the experiment, white noise excitation was applied using a speaker placed near the entrance, and the FRF was obtained by using a microphone placed at the outlet to measure the sound pressure. During this process, the analytical and experimental FRFs were compared to see whether they agreed (Fig. 18); the analytical FRF had a clear peak, but this peak was sharper in the experimental results, suggesting that damping did not act as strongly in the actual
experiment. However, overlapping the magnitude plots of the two results shows that the frequencies of the two methods match fairly well, verifying the analytical results (Fig. 19).