COVID 19 Precautionary Measures and Guidance for Live Sound Technicians.

updated 11/03/21 by Matt Royston-Bishop

Please exercise an appropriate level of caution or investigation prior to creating your own precautionary measures and procedures. There is lot that is not understood about COVID 19 and the purpose of this article is to create a starting point for anyone restarting live performances.

I have collected some useful links for background reading and summarised applicable and actionable points. It is worth reading them all.

Overview of the situation

The likelihood of virus transmission increases with duration and frequency of exposure of an uninfected individual with someone infected with the virus.

No non-essential people not connected with the production.
A stripped-down show (e.g The increased use of backing tracks to reduce performer numbers)
Design and implement systems that minimise interactions with performers and other staff.
Strive to maintain a 1m plus distance.
Be aware of who you are working with and track this.
Wash your hands thoroughly and regularly for 20 seconds before, during, and after handling a microphone or other item of equipment.
Ask and offer support to your colleagues.
Share and evaluate new knowledge and set up frequent reviews to revise working practices accordingly.
Wear a mask when maintaining a 1m plus distance is likely to be compromised. Masks alone will not prevent infection if the exposure is prolonged.
Don’t use your mobile phone.
Schedule staggered breaks and…
WASH YOUR HANDS!

Working safely with microphones

Microphones, especially those used for close-range speech require special care to avoid carrying the virus from one user to the next. Positioned close to the mouth the viral load (a numerical expression of the quantity of virus in a given volume of fluid) is high.

Have one user per microphone (including the accessories).
In some settings it is appropriate to wear a face covering but this would not replace the need to disinfect the microphone.

The most reliable way to make sure that a microphone is virus-free is to store it for a long enough time, i.e. for several days after use. If it hasn’t been touched or breathed on in 24 hours, it’s almost certainly safe; at 72 hours, you can take off the almost.

Is a live microphone necessary? “Voice of God” and announcements could be pre-recorded.
For low-level theatrical voice reinforcement, boundary mics could be an option.
Performers/Speakers to mic themselves up if possible. Be patient and provide clear directions.
Set up a Whatsapp group and ask performers/speakers to post photos to check mic positioning etc.
Create a clear pick-up and drop off zone for microphones, wireless packs, and battery. https://www.rfvenue.com/blog/2016/05/13/whats-up-with-the-tin-bins
Microphones and wireless packs clearly labelled (as always). Buy a Label printer and White text on black tape labels

An Example Microphone tracking and cleaning log spreadsheet template

Link

Using foam windscreens for protection

A foam windscreen will help, but it may not protect a microphone 100% from exhalations. If the microphone has a removable head basket then these could be exchanged.

To clean foam windscreens, both large and small, remove them from the mics and wash them gently with warm water and soap, rinsed in clean water, shaken to remove water droplets, and left to air-dry for at least 72 hours – this will allow time for any germs to die. Foam windscreens cannot be disinfected with isopropyl alcohol or other harsh chemicals.

How to disinfect microphones

The microphone housing can be cleaned with a cloth moistened with Isopropyl alcohol diluted to 70% with water.

To prevent damage to handheld microphones, great care must be taken to ensure that no liquid gets inside the microphone or (especially) reaches the diaphragm inside the microphone capsule. Do not soak the cloth in cleaner or disinfectant or use sprays, as these can deposit on the membrane and thus damage the microphone capsule.

Lavalier and headset mic capsules can be cleaned with Demineralised water and then left for 24 hours minimum. To disinfect, use Isopropyl alcohol diluted to 70% with water. Disinfecting the cable is necessary but will result in damage (the rubber becoming brittle) over time.

Buy 70% Isopropyl Alcohol on Amazon or from Theatre Sound Supplies

Surface Cleaner

In terms of the standard risk assessment methodology the risk component is determined by vulnerability and thus the familiar matrix is not a useful tool.

Venue size multiplied by 3. Portable sinks. Testing kits. Expect minimum 20% increase in production costs

Biggest compliance issue is Audience response. “Stamp your feet and clap your hands but please don’t cheer!”

Cultural imperative to continue to offer art

Orchestral wind instruments

Measurement of aerosol from brass and woodwind instruments

…tuba produces fewer aerosols than normal breathing, while the concentrations from bassoon, piccolo, flute, bass clarinet, French horn, and clarinet stay within the range of normal breathing and speaking. Trumpet, oboe, and bass trombone tend to generate more aerosols than speaking.

Aerosol generation from different wind instruments

Photos below from Vienna Philharmonic

Tagged #COVID19, #Microphones.