Surround-Sound ‘Audio Battlefield’ Reproduces Cacophony of War



Telecommunications professor Steven Grant of the Missouri University of Science and Technology has built a soundstage in a warehouse that accurately replicates the sound of a battlefield.
Army recruits are often overwhelmed by their first battlefield experiences, simply because of the volume of the explosions, gunfire and jets zooming overhead. The soundstage is designed to give troops some idea of what they’re in for, beforehand.

It comprises 64 speakers that can fire in small groups to aim sounds at a specific three-dimensional location. The low end is powered by four subwoofers, and it’s all hooked up to a truss that measures 12 meters by 6 meters by 5 meters [39.4 feet by 19.7 feet by 16.4 feet]. Inside that truss, a small unit has enough space to perform maneuvers in full gear, complete with an appropriate soundtrack.
Wired.co.uk spoke to Steven Grant about the project, to ask a few questions about how it works.
Wired.co.uk: How are the sounds generated? Are they recordings from a real battlefield, or artificially generated?
Steven Grant: We have recordings of various sound elements like AK-47s, M-16s, tanks, helicopters, etc. from various sources. These sounds are then synthetically moved around the IAE [immersive audio environment] by our software.
Wired.co.uk: How long does a user generally stay inside the simulator? How long is it safe to stay inside the simulator?
Grant: With our current implementation of battle sequences you can stay in the IAE without any hearing loss for about two hours per day without using hearing protection. Right now we are generally running at a maximum of about 100 decibels. Of course, real battles sounds are much louder, but we conform to OSHA [Occupational Safety and Health Administration] guidelines.
Wired.co.uk: What are the benefits of the training simulator for soliders?
Grant: We are currently studying that. I have teamed with a psychologist from our university, and we are doing some experiments on student volunteers later this summer and fall to measure the benefit of training in an audio-battlefield environment. We anticipate that the IAE will help soldiers become habituated somewhat to the battle environment prior to their actual exposure.
Wired.co.uk: Finally, what are the elements that the system comprises?
Grant: The list of electronic devices is as follows (quantity in parentheses):
  • RME M-32 AD (2) used for the 64 channels of digital-to-analog conversion
  • MPS-488E (6)  power supplies for the Meyer MM-4XP’s
  • RME Micstacy (1) preamp and analog-to-digital conversion for microphones (8 channels)
  • RME ADI-648 (1) currently not used
  • RME Octamic II (7) currently not used
  • Mackie HR824 (12) main speakers
  • Meyer MM-4XP (44) satellite speakers
  • M-Audio SBX10 (4) subwoofers