Tacoma Narrows Bridge (1940) Billah and Scanlan (1991) reported that in fact, many physics textbooks (for example Resnick et al. and Tipler et al.) wrongly explain that the cause of the failure of the Tacoma Narrows bridge was externally forced mechanical resonance. Resonance is the tendency of a system to oscillate at larger amplitudes at certain frequencies, known as the system's natural frequencies. At these frequencies, even relatively small periodic driving forces can produce large amplitude vibrations, because the system stores energy. For example, a child using a swing realizes that if the pushes are properly timed, the swing can move with a very
Amplitude panning sound image. However, it was suggested that the localisation at relatively high frequencies may take advantage of the interaural level difference resulting from the head-shadowing effect. For the frontal standard configuration, the relation between the inter-channel level difference and the perceived image position has been investigated in many studies, where the target positions were found to be slightly overestimated in many cases. Similar listening tests were also carried out for some asymmetrical lateral configurations, and the results showed that the amplitude-panning method is not as efficient in presenting images to listener’s side as it is to the front. Amplitude panning