Communication assembly, aircraft provided with the communication assembly and method for preventing interference in communications

A communication assembly for avoiding interferences due to oxygen flow noise in communications between a user, an aircrew member, and another aircrew member or between the user and a control tower, said communication assembly comprising:

• a) a breathing mask including:
• a body having a face shell having a breathing cavity, said face shell being adapted to be applied on a face of the user in a use configuration in which the breathing cavity is delimited by said face shell and by the face of the user, and
• a regulator including an inlet orifice intended to be connected to an oxygen source and an outlet orifice delivering a breathing gas containing oxygen, the outlet orifice being in flow communication with the breathing cavity for supplying the breathing gas to the user in a flow through the breathing cavity during inhalation by the user,
• b) a test button for supplying the breathing cavity with breathing gas when the communication assembly is in a stowed configuration in which the breathing cavity is not in contact with the face of the user,
• c) a microphone mounted on the body of the breathing mask, the microphone being configured to capture a sound signal in the breathing cavity and transmit a first electrical signal corresponding to the captured sound signal,
• d) an attenuation device configured to receive the first electrical signal and operate in at least a first mode or a second mode and transmit a second electrical signal, wherein:
• in the first mode, the attenuation device attenuates at least one central frequency band of the first electrical signal, said central frequency band corresponding to a frequency range of the sound signal extending between 500 Hz and 1,500 Hz, and
• in the second mode, the attenuation device does not attenuate the central frequency band of the first electrical signal;
• e) a sound monitoring system comprising:
• a first sound monitor configured to monitor the sound signal, detect a first sound intensity in a first frequency range and analyse the first sound intensity to determine whether the first sound intensity is within a first determined level range to detect a flow noise through the breathing cavity during inhalation by the user in the use configuration, and
• a second sound monitor configured to monitor the sound signal, detect a second sound intensity in a second frequency range and analyse the second sound intensity to determine whether the second sound intensity is within a second determined level range to detect a vocal sound, the second frequency range being distinct from the first frequency range;
• f) a controller configured to select the operating mode of the attenuation device, in order to make the attenuation device operate in:
• the first mode when the first sound intensity analysed by the first sound monitor is within the first determined level range and when the second sound intensity analysed by the second sound monitor is not within the second determined level range, and
• the second mode when the second sound intensity analysed by the second sound monitor is within the second determined level range;
• and
• g) a transmitter disposed downstream of the attenuation device for transmitting an output signal to another crew member or an emitter antenna,
• wherein:
• the sound monitoring system is configured to monitor the sound signal, detect a third sound intensity in a third frequency range and analyse the third sound intensity to determine whether the third sound intensity is within a third determined level range to detect a flow noise in the breathing cavity in the stowed configuration, the third frequency range being distinct from the first frequency range, and
• the controller is configured not to make the attenuation device operate in the first mode when the third sound intensity is within the third level range.