LUND Sweden — The coronavirus pandemic is giving new meaning to the phrase “silence is golden.” As scientists examine how COVID spreads through the air, a new study finds singing may be the worst thing you can do around other people. Researchers in Sweden say even speaking certain letters can increase the spread of infectious particles into the air.
Aerosol researchers at Lund University say there is already evidence of people getting sick at social gatherings which feature singing. Still, few scientists are actually measuring if carrying a tune carries more virus particles.
“There are many reports about the spreading of COVID-19 in connection with choirs singing. Therefore, different restrictions have been introduced all over the world to make singing safer. So far, however, there has been no scientific investigation of the amount of aerosol particles and larger droplets that we actually exhale when we sing,” Jakob Löndahl says in a university release.
Singing for science
To test their theory that singing could have “super-spreader” potential, the Swedish team recruited 12 healthy singers and two people testing positive for COVID-19. Seven of these volunteers are professional opera singers.
Wearing a clean air suit in a special chamber, filled with filtered and particle-free air, the participants were examined while breathing, talking, and singing with and without a face mask. Researchers asked the singer to recite the Swedish song “Bibbis pippi Petter” normally and with the consonants removed, leaving only vowels in the lyrics.
Using a high-speed camera, strong lamps, and particle-measuring instruments, the study reveals loud and consonant-rich singing spreads aerosols and other droplets into the air. The louder the singing is, the greater the particle concentration becomes. Songs using words with two letters in particular can significantly increase the spread of viruses.
“Some droplets are so large that they only move a few decimeters from the mouth before they fall, whereas others are smaller and may continue to hover for minutes. In particular, the enunciation of consonants releases very large droplets and the letters B and P stand out as the biggest aerosol spreaders,” explains aerosol technology doctoral student Malin Alsved.
Face masks, social distancing still best for stopping COVID spread
The study shows that the two participants with COVID had no detectable levels of the virus in their air samples while singing. They caution however that viral loads can differ from patient to patient.
“Accordingly, aerosols from a person with COVID-19 may still entail a risk of infection when singing,” Alsved says.
When it comes to singing in public, chanting at sporting events, and concerts of all kinds, researchers recommend continuing social distancing and good hygiene practices. This latest COVID research shows that when the singers wear face masks, aerosol levels drop to the same amount as someone speaking normally.
“Singing does not need to be silenced, but presently it should be done with appropriate measures to reduce the risk of spreading infection,” Löndahl explains.
The study appears in the journal Aerosol Science and Technology.