How to manage Noise in a large control room with many Consoles.

We have a customer struggling with audio noise in the control room, with multiple consoles, each with Radio stations, DCS consoles (alarms), Public Address announcements and such.  Each console can have several people engaged in discussion, which leads Operators to turn up their audio outputs, which leads to every increasing levels of noise, making everything difficult to hear.

One solution proposed was the use of directional speakers in each console in a control room, but with multiple audio sources per console, having multiple speakers still creates noise competition.  We were asked if there was a solution that would allow multiple Audio sources to be connected together where a priority could be set on the input signals such that when two or more signals are present at the same time, the system can reduce the audio level based on priority to ensure the priority audio signal is clear.  The other signals return to normal based on priority, resulting in a quieter environment and one directional speaker per console.

I thought I'd ask the community to see if this type of solution already exists.  With today's technologies it seems quite plausible that a multi input audio device could detect signal levels/presence and auto adjust channel gain to prioritize the Alarm Horn over Radio, but the Radio over the PA or other audio signal.  With one directional speaker per console to manage, the ambient noise level would drop, allowing conversations to also remain at lower volume.  

What do you do in your control rooms and consoles to manage noise levels?

Andre Dicaire

5 Replies

  • Trying to remember something I heard before I thought it was about dealing with sound in an air traffic control room.
  • I may have a candidate for you - sending to your Outlook Inbox.
  • Another technology out there is Bone Conductive headphones. These headphones go around the ear, leaving the ear canal open, so the user can hear the audio and any conversations around them. The headphones vibrate such that only the user wearing them can hear the audio. This could reduce the noise in the control room but still allow the operator to partake in conversation.

    The one downside would be that if the operator is not wearing them, then they will not hear the alarm either.
  • A white noise generator might help limit the noise levels in the control room.
  • In reply to István Orbán:

    I found some information from a consulting firm out of Europe that talked directly to noise management in the control room.

    (Company name was GESAB and article was "the importance of acoustic comfort in control room design")

    The raised the importance of sound reverberation in the space, which is mostly how long a sound remains audible as it bounces around the room. They set a target for this reverberation (between 0.4 to 0.75 sec) Too dry is disconcerting. Then they add noise abatement surfaces on the floor, walls and even baffles on the ceilings.

    The other insight I received from an Audio Engineer is to block direct path of the noise. Even if this is glass, or some clear plastic, the sound has to bounce around to get somewhere, and if the ceiling, walls and floor are noise absorbing, sound doesn't go far.

    Focused sound sources that reduce the contribution of noise were not mentioned, and short of using headsets, impossible to eliminate in an open space. If you direct the sound such that it hits noise absorbing surfaces such that it is not given a chance to escape into the room (much) that helps. Desk mounted speakers facing out to the operator but also the larger room might be moved to be mounted more to the rear of the operator and pointing to the console desk, and noise abatement rather than the consol opening to the room.

    There are lots of examples of large control rooms with dozens if not hundreds of individuals seated at their consoles sitting 5 feet from others. These seem to always use headsets, which do two things, focus the audio for the user and also capture only their voice in a mic for clear communications.

    Which makes me think that a single ear head piece for the radio with a microphone would be the lowest cost solution for this, allowing the operator to maintain audio connection to the console for Alarm horn or other communication in the room. it would cut the radio as a source of noise for the room. A radio speaker would still be there if several individuals need to hear the conversation, but if the headset is engaged (pick it up from the cradle) the speaker is silenced and the radio conversation is clear for both parties. But everyone sharing headsets is not recommended, or at least, the ear and mouth pieces must be personalized/sanitized between individuals.

    Also, having a visual cue when attention is needed complements things like alarms. They don't need to be as loud and heard all over the control room, maybe. or when an alarm is heard, where its coming from is clearly seen.

    Each control room is different, but the Audio aspect of ergonomics needs to be part of the design solution. Industrial control rooms have a lot more human interactions than those large control centers or dispatch centers. The concept of managing the reverberation level as a concreate measurement I think makes a lot of sense. That should be the first level of design that sets up the space for success.

    Much like making sure your control valve is functioning optimally is your best chance of attaining desired control response. If you start with the wrong or a bad valve, adding more control logic is never going to be as good as fixing the control element. 

    Thanks for everybody's contribution.

    Andre Dicaire