System comprising a source device and an acoustic processing device, wherein: the source device comprising: - a first interface intended to be connected to a sound reproduction device, and, - a second interface intended to be connected to the acoustic processing device, the acoustic processing device comprising: - at least one third interface (121; 122) intended to be connected to at least one microphone (111, 112), - a fourth interface intended to be connected to the source device, the system comprises means for implementing an initialisation phase comprising: - an acoustic processing unit of the acoustic processing device adapted for delivering to the source device, via the fourth interface, a first audio signal received via the third interface, - a control unit of the source device adapted for: ∘ determining a propagation latency between an instant of transmission of a second audio signal via the first interface and an instant of reception of the first audio signal via the second interface, ∘ configuring a buffer of the source device with a reading-triggering threshold defined according to said determined propagation latency, and in that the source device further comprises means for implementing a nominal operating phase comprising: - the acoustic processing unit adapted for transmitting to the source device, via the fourth interface, an audio signal filtered by attenuation or suppression of a reference audio signal from an audio signal received via the third interface, the reference audio signal being transmitted by the buffer of the source device via the fourth interface, - an audio signal supplying unit adapted for transmitting an audio signal via the first interface, the reference audio signal used by the acoustic processing unit resulting from a passage of said audio signal through the buffer. the source device comprising: - a first interface intended to be connected to a sound reproduction device, and, - a second interface intended to be connected to the acoustic processing device, - a first interface intended to be connected to a sound reproduction device, and, - a second interface intended to be connected to the acoustic processing device, the acoustic processing device comprising: - at least one third interface (121; 122) intended to be connected to at least one microphone (111, 112), - a fourth interface intended to be connected to the source device, - at least one third interface (121; 122) intended to be connected to at least one microphone (111, 112), - a fourth interface intended to be connected to the source device, the system comprises means for implementing an initialisation phase comprising: - an acoustic processing unit of the acoustic processing device adapted for delivering to the source device, via the fourth interface, a first audio signal received via the third interface, - a control unit of the source device adapted for: ∘ determining a propagation latency between an instant of transmission of a second audio signal via the first interface and an instant of reception of the first audio signal via the second interface, ∘ configuring a buffer of the source device with a reading-triggering threshold defined according to said determined propagation latency, - an acoustic processing unit of the acoustic processing device adapted for delivering to the source device, via the fourth interface, a first audio signal received via the third interface, - a control unit of the source device adapted for: ∘ determining a propagation latency between an instant of transmission of a second audio signal via the first interface and an instant of reception of the first audio signal via the second interface, ∘ configuring a buffer of the source device with a reading-triggering threshold defined according to said determined propagation latency, ∘ determining a propagation latency between an instant of transmission of a second audio signal via the first interface and an instant of reception of the first audio signal via the second interface, ∘ configuring a buffer of the source device with a reading-triggering threshold defined according to said determined propagation latency, and in that the source device further comprises means for implementing a nominal operating phase comprising: - the acoustic processing unit adapted for transmitting to the source device, via the fourth interface, an audio signal filtered by attenuation or suppression of a reference audio signal from an audio signal received via the third interface, the reference audio signal being transmitted by the buffer of the source device via the fourth interface, - an audio signal supplying unit adapted for transmitting an audio signal via the first interface, the reference audio signal used by the acoustic processing unit resulting from a passage of said audio signal through the buffer. - the acoustic processing unit adapted for transmitting to the source device, via the fourth interface, an audio signal filtered by attenuation or suppression of a reference audio signal from an audio signal received via the third interface, the reference audio signal being transmitted by the buffer of the source device via the fourth interface, - an audio signal supplying unit adapted for transmitting an audio signal via the first interface, the reference audio signal used by the acoustic processing unit resulting from a passage of said audio signal through the buffer.