A system for diffusing audio signals by means of an optical radiation, comprising: - at least one first and one second optical transmitting module (99', 99"), each comprising at least one photoemitter emitting an amplitude modulated optical radiation, said first and said second optical transmitting module (99', 99") transmitting a first and a second modulated optical radiation according to a first and respectively a second signal at least of the audio type (s1(t), s2(t)); - at least one optical receiving module, comprising: - at least one photoreceiver adapted to receive said amplitude modulated optical radiation from at least one of said optical transmitting modules (99', 99"), - at least one AM demodulator, electrically connected to said at least one photoreceiver, configured to extract, in use, a replica of said audio signal transmitted through said at least one first and/or second optical transmitting module (99', 99"); wherein said optical receiving module is configured to generate, on at least one first output thereof, a replica electrical signal (s'(t)), replicating said signal at least of the audio type transmitted from said at least one first and/or second optical transmitting module, so that: - if only the first optical radiation is received, it replicates said first signal at least of the audio type (s1(t)); - if only the second optical radiation is received, it replicates said second signal at least of the audio type (s2(t)); the system being characterized in that - if both the first optical radiation and the second optical radiation are received simultaneously, it replicates said first signal at least of the audio type (s1(t)) mixed with said second signal at least of the audio type (s2(t)), wherein the at least instantaneous intensity of the replica of said first signal at least of the audio type (s1(t)) and of the replica of said second signal at least of the audio type (s2(t)) is proportional respectively to the intensity of said first optical radiation and/or of the modulation thereof, and to the intensity of said second optical radiation and/or of the modulation thereof. - at least one first and one second optical transmitting module (99', 99"), each comprising at least one photoemitter emitting an amplitude modulated optical radiation, said first and said second optical transmitting module (99', 99") transmitting a first and a second modulated optical radiation according to a first and respectively a second signal at least of the audio type (s1(t), s2(t)); - at least one optical receiving module, comprising: - at least one photoreceiver adapted to receive said amplitude modulated optical radiation from at least one of said optical transmitting modules (99', 99"), - at least one AM demodulator, electrically connected to said at least one photoreceiver, configured to extract, in use, a replica of said audio signal transmitted through said at least one first and/or second optical transmitting module (99', 99"); wherein said optical receiving module is configured to generate, on at least one first output thereof, a replica electrical signal (s'(t)), replicating said signal at least of the audio type transmitted from said at least one first and/or second optical transmitting module, so that: - if only the first optical radiation is received, it replicates said first signal at least of the audio type (s1(t)); - if only the second optical radiation is received, it replicates said second signal at least of the audio type (s2(t)); the system being characterized in that - if both the first optical radiation and the second optical radiation are received simultaneously, it replicates said first signal at least of the audio type (s1(t)) mixed with said second signal at least of the audio type (s2(t)), wherein the at least instantaneous intensity of the replica of said first signal at least of the audio type (s1(t)) and of the replica of said second signal at least of the audio type (s2(t)) is proportional respectively to the intensity of said first optical radiation and/or of the modulation thereof, and to the intensity of said second optical radiation and/or of the modulation thereof.