Cardiovascular Sound in Health and Disease

The author of this monumental work has gone into great detail in describing how the cardiac sounds and murmurs are produced and how they can best be recorded. There is an excellent chapter on the stethoscope and the art and practice of cardiac auscultation. Phonocardiography is fully described, taking into account the advantages and limitations of various methods used. The recording method used by the author is known as spectral phonocardiography, an application of the method of sound spectrography developed at the Bell Telephone Laboratories. The sound recording is usually first made on magnetic tape. Then a segment of sound is selected for analysis and played over on the edge of a magnetic disk. This permits repeated playback. Visual records of the sound can be made at different frequency bands for analysis. Records of heart sounds and murmurs have become increasingly important in recent years as part of the determination