Early research on muscle sounds

Summary form only given. A survey of research on muscle sounds is presented, beginning with experiments dating back to 1665 and covering research through the 1900s. The early belief was that muscle sounds were due to the movement of animal spirits. W.H. Wollaston (1810) attributed muscle sounds to repetitions within the muscle mass of small contractions. According to H. Helmholtz (1867), the muscle sounds consist of almost periodic vibrations. Research in the 1800s on sounds produced by facial muscles is discussed.<
>