Aigner A, Wieser M, Müller G, Raas E
Z Kardiol. 1977 Jun;66(6):319-22.
The acoustic transmission characteristics of the human thorax in the frequency range of 100 to 2000 c.p.s. were studied in nine corpses. Using a logarithmic scale for frequency, the sound pressure level measured on the chest wall showed a linear attenuation between 100 and 1000 c.p.s. with a mean reduction in sound pressure level of 77 dB.