System and method for compensating distortions introduced by an optical channel and by at least one directly modulated transmitting laser that transmits a modulated optical signal that carries data to a receiving end over the optical channel. A priori noise suppression is applied to the speech signal of each frame on the basis of estimates of the noise obtained on processing at least one preceding frame, and the energy variations of the a priori noise-suppressed signal are analyzed to detect the degree of vocal activity of said frame. , disrupting biofilms, preventing biofilm formation, enhancing biofilms, or modifying biofilms. Convenient and economically feasible processes by which the tablets of the invention may be produced are also provided.