Bowditch impressed Ludwig by constructing an improvement on the kymograph then in use. Next in 1879, an innovation to listen to muscle movements using a kymograph was implemented. Consequently, some microtubule processes can be determined by kymograph. J. H. Bair conducted experiments on humans, using a kymograph to measure their ear movements. The kymograph almost immediately became the central instrument in physiology and physiology education. Kymograph is generally used to study the effects of xenobiotics on tissue preparations.