When working in noisy environments the background noise changes constantly. The same does the level of your speech. The human brain simply adjusts the speaking level according to surrounding noise. During the day, and even during a conversation, we constantly adjust our voice to a desired level.
For the very same reason any VHF radio has an adjustable Squelch,that set the noise cut off to a reasonable level. But it only works for the radio - what about each user in a larger intercom setup. Is your intercom VOX operated or a fully open circuit ? Wind noise, engine noise and even breathing,can easily open the microphone, which requires either a constant adjustment of the squelch or the squelch level to be set so high, that very loud speaking is necessary no matter background noise level. AVAD takes care of that. iriSound's new DSP Software listens and adjusts that for each channel independently.
AVAD - means that each user in a multiple-user scenario will achieve silence, and only a slight word willactivate and open the microphone circuit.