UC/CCM COVID research: How bad is the news for voices and winds?

The COVID-19 pandemic that continues to kill thousands of people has curtailed many of our society’s most basic activities. 

Musical performance, we quickly discovered, is an especially risky activity for transmitting the virus – groups of people gathered close together to sing or play instruments. That fact hit home early in March when one member of a community chorus in Washington state infected 52 fellow singers, leading to two deaths. 

Now, a first-ever study at the University of Cincinnati has looked at just how performing music can spread this virus – and what musicians can do to reduce the risk. Hundreds of musicians and health professionals viewed a July 29 webinar announcing the findings.

The results, frankly, aren’t good, especially for singers.

“The general conclusion is that singing is not encouraged,” said Jun Wang, a professor in Environmental and Public Health at UC’s College of Medicine, who led the study.

“Most likely, singing without any interventions, without masks or anything, will be the primary of source of transmission in a musical group. In a choir, many people are singing close together, and that is a problem.”

The issue, Wang said, is that the act of singing can explosively release particles into the air, many times more than in normal speaking – both as droplets, which fall fairly quickly to the ground, and smaller aerosols, mist-like particles under 5 micrometers in size (the exact cutoff is debated) that waft and drift and linger in the air.

Instrumental performance isn’t as problematic, but trumpeters, clarinetists and even violinists don’t get a pass on the COVID-19 dilemma either, the study found.

Though there’s no definitive data yet on exactly how and how strongly COVID-19 is spread, Wang thinks it’s clear:

“Because of my training in aerosols and my experience, I think this is a combination of aerosol and droplet transmission,” he said. “It’s not one or the other. You have both at the same time, so you have to protect yourself against both.”

Wang and his colleagues worked with faculty and student musicians at UC’s College-Conservatory of Music, led by saxophonist James Bunte, head of the Performance Studies Division.

They performed various tests to determine how particles are spread in vocal and instrument performance. Not surprisingly, the results of the month-long study varied greatly depending on the instruments, the voices and the individuals behind them.

“In singing, everyone is different in how they emit aerosols or droplets,” Wang explained. “Someone singing at a higher volume or higher pitch or frequency will typically generate more aerosols. It also depends on how they breathe.”

With musical instruments, Wang added, there are even more variables involved. “They are so complex and varied in design, depending on the materials, how they are constructed, the bell shape, the size, the valves … Some instruments intentionally leak air. Some instruments have so many holes, you don’t know where air exits, to what extent and in what directions – like a trumpet in front of your face, a tuba upward, a flute sideways, a French horn backward. Everything is different.

“All these are factors, and this is besides the human factor, because again, there are differences between people. But generally, we saw that aerosol emissions from woodwind and brass instruments are less compared to people singing.”

It’s not just about singing and wind instruments, either. “Everyone in music is affected. Even your string players sitting together can have an effect by just speaking.”

All these variables, of course, make possible solutions – the second point of the UC study – more problematic.

“We are looking at some kinds of interventions and controls that can help,” Wang said. “The distance indicated from one performer to another actually goes beyond the six feet that is usually recommended based on respiratory droplets, but for aerosols is actually not that effective at all. So we would suggest as much as possible, 10 feet, 12 feet or even beyond that.”

That kind of spacing could lead to interesting musical effects in choral singing – indeed, having singers placed far from each other throughout an auditorium has to be done on purpose with certain types of music.

But given the nature of aerosols, even more intervention may be needed with choral singing.

“Some people are developing face masks for singing, but generally when people sing and wear a face mask their voices will be muffled. Using some kind of microphone could work around that, but you lose the natural sound, so that’s a problem too.”

Removing virus-bearing particles from the air could be part of the solution.

“Another way we can do this is to use some portable units, air purifiers, among the musicians. They have to be very carefully placed around and within the singing group.”

EDITOR’S NOTE: According to this research, the use of HEPA filters does show great promise in mitigating aerosol spread, and could prove especially helpful in teaching situations. Investigations continue.

The noise from purifier fans, Wang said, shouldn’t be significant. “Well, if you have a hundred of them, yes, but if you have a handful of them placed on the floor I don’t think so. Of course, the higher you run them the more efficiently they filter the air, but the more noise they make.”

Other interventions the researchers identified involved modifying instruments, sealing and covering parts of the instruments to reduce air flow – again, measures that could hurt musical quality.

“The wonder of the music is that you have the harmony and blend of the sound, and now it’s going to be muffled. It is going to be hard in real-world practice,” Wang said.

Why go through all this effort? 

“The reason we are doing this and rushing our results is that there are many people who really need to know about these things and have some sense about what they can do,” Wang said. “People are anxious to go back to musical performance and education. School will start. There will be music education, music classrooms. Singing or choir practice. Marching bands. There are certain orchestras in the country that actually are performing. So they need to be cautious.”

These cautions go beyond those we’ve become accustomed to in our daily lives.

“If you go to the store and maybe you buy something, you’re not going to talk loud, you’re just quietly going to wear your face mask, grab your groceries and go back home,” Wang noted. “But for singing and any musical performance it’s a different story. They’re unique in the way that you use your vocal cords, your airways. Anything in your airways like mucus or saliva — when the vocal cords vibrate, they create a whole different situation.”

The just-announced results, Wang said, do not mark the end of the UC study, only the beginning. “We will have many more studies coming, tests done in a controlled environment with different variables and interventions. We also want to do simulations of airflow to see patterns of aerosol concentrations. Even if COVID-19 disappears tomorrow we are still going to do these studies – but it’s going to be here for a while.”

Music, Wang said, is too important to lose during these times. “I don’t think we should just say, ‘OK, stop singing,’ or ‘You shouldn’t do this or that.’

“Music plays a very unique, important function in our society. Music is a wonder,” Wang said. “It helps ease people’s minds, healing our wounds, relaxing our anxieties and stress. That’s why we want music back.

“We just need to find an approach to safely do that.”