[The high frequency components of the heart sounds in normal subjects (author's transl)]

A technical set up for recording high frequency components of the cardiac vibrations is described. This was based on the use of several amplifiers, taking the third derivative of the displacement tracing, and using a high pass filter with a sharp slope. The tape-recorded high frequency tracing, at 500 Hz, 1000 Hz, or higher, was replayed at slower speed for accurate recording of the high speed signals. A study of the first and second hearts sound at 500 Hz and 1000 Hz was made in 14 young, normal volunteers. The high frequency vibrations of these sounds are analyzed and discussed.