An in vitro experiment is carried out in order to study the acoustic e!ects of a vascular constriction (stenosis) in people and provide correlations between these e!ects and parameters relevant to the hydrodynamic and acoustic processes. For this purpose, we measure the sound produced when water #ows through an elastic tube which is either unobstructed or contains a rigid axisymmetric constriction. The sound is measured at the outside of a large annular container "lled with water and bounded at the inside by the coaxial elastic tube. The analysis of the acoustic "elds shows that a stenosis has two basic acoustic e!ects. These are a general increase in the sound level and the production of a number of additional distinct peaks (new frequency components) in the acoustic power spectrum. The frequencies of these peaks are close to the characteristic frequencies of vortex formation in the disturbed #ow region behind a stenosis and the resonance frequencies of vibration of the post-stenotic segment of the tube. Another important result is that the stenosis generated acoustic power is approximately proportional to the fourth power of the stenosis severity and the same power of the #ow Reynolds number.