A duck's quack is often said not to echo, but this claim is a myth. Physics can explain that while parts of a duck's quack may produce echoes, the phenomenon is not fully understood. Acoustic experts, including those featured on Mythbusters, have analyzed the quack and reached similar conclusions regarding its sound behavior. The uncertainty surrounding the quack's echo relates to the complexities of sound absorption and reflection. Ultimately, the reasons behind this acoustic behavior remain unclear.