Fix nearly unavoidable nightmare audio

Hi all

Equipment I’m using:
Panasonic HC-V770
Access to Blue Snowball but can’t always use it
Windows 10
Add-ons: Neutron 2 and RX 7

I work in the simulation department at a hospital. Lately we’ve been doing a lot of in-situ simulations with recordings in order to improve processes and find possible weak points that may affect patient outcomes or staff safety. As a result of this, I’ve got a number of nightmare issues regarding the recording of audio;

    • There may be potentially COVID positive patients in the area, so masks must be warn at all times which causes some muffling and other issues
      The sims are designed to be as real as possible, so people don’t always know when they are being called on, making mic’ing impossible
      People are all over the place with multiple conversations happening at once
      There’s always patient monitor noises in background
      Ventilation noises EVERYWHERE. Every room has some form of significantly strong ventilation
      Quite often moving from one area to another with different beeping/ventilation

I COMPLETELY understand that this will never be close to studio or anywhere near high quality, but it’s important that voices can be somewhat understood. This will mostly be reviewed by the professionals and not presented so doesn’t need to be the most professional. I’m a video guy, but have an annoyingly good ear for bad audio. I somehow have access to Neutron 2 and RX 7, and I’m pretty good at using them and other audacity tools for polishing decent mic recorded audio, but every time I do anything with this audio, I end up with the talking into a wineglass or garbled voices audio. On occasion I can hook up a blue snowball, which in omni directional mode does a relatively better job then the camera mic, but it’s rarely possible to use it based on the different situations. We’re a public hospital on public money, so budget is almost non-existent, and worse now that the majority of funds are going towards patient care (for good reason).

I’ve mostly got two questions:

  1. Is there anyway to clean up the camera recorded audio? I have spent literal days trying many different things posted on here with little success in this situation.

  2. Is there any cheap ways to improve the initial recording, given that shotgun mics are out of the question because people are talking all over. Can’t mic. Can’t stage people appropriately. Etc.

I’ve attached two files, one is the 5.1 output from the camera in MP3 format with a decent length and the other is the stereo wav output but had to lower the bit depth to 8, not sure which is more useful, or let me know what might be better.
Any help that can be provided is greatly appreciated!

The only trick I know of is to shoot it in wide stereo. I set that up for a director’s screening of a production we were working on. I mic’ed the screening room with two directional microphones a good 9 feet apart pointing back to the audience plus a lower volume mono mic in the center. I hid the tiny sound mixer under the screening room control desk and since the sound was now powerful line-level, I shipped the sound to a different room where I recorded it…in Audacity.

I used additional tricks like pressure-zone configuration with my regular rock-band microphones…which I have a picture of here somewhere.

If you listened to the stereo playback on stereo headphones, you could clearly hear the Director and Producer comments from straight in front, one of the production assistants wondering about cookies for the snack table on the left and the AD on the right complaining about the horrendous freeway traffic getting here.

All clearly audible and all at the same time.

That’s it. Same problems. They would probably sit still for being mic’ed if I insisted, but my managers would not be pleased. The goal was to listen to Director’s comments if you weren’t there.

You don’t need the lecture about not being to get to reality by starting out with reality. See: Hollywood.

And you should know there are no reliable ways to split a mixed sound track into individual voices, instruments or sounds.

She settled on double-stuff Oreos. Good choice.

Koz

SM58PressureZone.jpg
That’s pre-production experiments. By the time I installed them, they were round and painted flat black and sitting on heavy black felt. That’s a Shure SM58 from any rock band. I drilled a shallow round hole under the mic head to keep it from rolling around. That’s black electrical tape on the back.

Pressure Zone is a big deal because it doubles the volume of the microphone with good quality and no increase in noise. You just have to put it on a towel, blanket, or Duvetyne to keep it from picking up floor or desk noise.

I shot the actual room in use. I need to go back and find that picture.

Koz

Since there is video, if you can make-out what’s being said subtitles can be very helpful.

I would narrow the stereo-image, make it louder, roll-off frequencies below 200Hz & above 10kHz …

Just a longshot…

Have you tried PZM mics on the wall or ceiling? These have somewhat less problems with reflections and since hospitals (and especially operating rooms) tend to be rather reflective, it could help with legibility.

Have you tried PZM mics on the wall or ceiling?

Pressure Zone Microphone. That’s the formal version of the rock band microphone glued to the piece of plywood. That trick has been around for a while.

That showed up here.


Any other restrictions?

You have to mic chaos with no money.

Round up a couple of iPhones, run Voice Memo and duct tape them on the walls. Make sure you get the microphones up or facing out.




As a first guess, say four to six feet on both sides of where you’re standing. Mix all three tracks later.

This is SWAG Engineering. Scientific Wild-Ass Guess. It might work, it can’t get a lot worse and there are few other options.

Koz