The acoustic signal from the sonochemical production of H2O2 in water, as m
easured by the intensity and the width of the second harmonic, show a sensi
tive and correlated dependence to the presence of small amounts (millimolar
range) of an; anionic surfactant (SIDS) In water. The graphic shows the li
nk from the ultrasonic reaction to the measurable quantities. New possibili
ties to reliably control such processes is therefore opened.