New German study: 1.5 metres is unsafe for singers

New German study: 1.5 metres is unsafe for singers


norman lebrecht

July 03, 2020

The chorus of Bavarian Radio commissioned a scientific report on the Covid-19 risks associated with singers. The results make uncomfortable reading.

Here’s an initial summary in English (German original here):

Aerosol study with the choir of the BR: First results
Scientists from Munich and Erlangen are studying corona infection risks when singing

What is the risk of getting infected with the corona virus while choral singing? And how can this risk be minimized? After contagion cases in choirs in the USA, Amsterdam, but also in Bavaria and Berlin, Bayerischer Rundfunk conducted an extensive test series for its orchestras together with the LMU Clinic Munich and in cooperation with the University Clinic Erlangen (FAU).

The first partial results of the scientifically unpublished study are now available.
In it, the participating scientists set out the circumstances under which they consider singing in corona times to be responsible for health – with a view to the distance between the singers and the indoor climatic conditions.

“After the first shock of the lockdown and examination of the restrictive requirements, we quickly became active together with our BR company doctor, Dr. Benthaus, under what conditions and with what repertoire the artistic operation could be resumed – provided that protection and the health of our choir members has top priority. In the weeks before it had become more and more clear that pure droplet infections could not be an adequate explanation for the high number of infections especially in choirs “, Susanne Vongries, manager of the choir of the BR, describes the initial situation.

However, since there is very little reliable scientific knowledge about contagion risks within vocal ensembles worldwide, the BR sought technical advice from Prof. Dr. Matthias Echternach, head of the department for phoniatrics and pediatric audiology at the LMU Clinic Munich and self-trained singer.

“With Prof. Dr. Echternach and Dr. Stefan Kniesburges from the University Hospital Erlangen, we have found promising partners with whom the study was prepared and implemented in a very short time. From the beginning, the members of the choir have also been very committed to serving them Data collection provided to generate new knowledge, “said Vongries.

The course structure

Together with Stefan Kniesburges, fluid mechanic at the University Hospital Erlangen (FAU), Matthias Echternach designed a study to measure the radiation and distribution of both larger droplets and small particles – the so-called aerosols – when singing, speaking and singing texts . The peculiarity: In contrast to studies relating to flow velocities of particles, the spread and distribution of the droplets and aerosols in the room were examined in more detail in these experiments.

To this end, the scientists set up two test arrangements in Studio 2 at the Unterföhring site in BR. In these two settings, from May 20 to 26, 2020, they had ten subjects from the choir of the BR and ten wind players from the symphony orchestra of the BR sing, speak and speak consecutively at different volumes. The data evaluation for the measurements with the wind instruments is still pending.

Aerosol clouds made visible and measured

The first setting consisted of high-speed cameras and laser equipment, with which the scattering of the larger droplets could be investigated: how are they emitted by the mouth and instrument, which speech or singing passages generate the largest amount of droplets?

In the second setting, cameras and white light were used to analyze how the even smaller aerosols leave the mouth and nose and how they spread into the room. In order to make the distribution of these tiny particles visible, the subjects inhaled a carrier solution of e-cigarettes, which was then visible in bright light during and after the vocalization.

Conclusion: More distance to the front than to the side

The evaluation of the measurements over the emitted aerosol clouds showed: The choir members should keep a greater distance from their colleagues in front than to the side. Always provided that the room is permanently ventilated and that the aerosols are regularly removed by fresh air. It would also be better if there were partition walls between the singers.

“We measured an average distance of a little less than one meter for the sung text, but some singers also reached distances of 1 to 1.5 meters, so that safety distances of 1.5 meters are probably too small and distances of 2 to 2.5 meters may seem more sensible, but the data only refer to the direct propagation through the self-impulse when singing, but for the safety of the singers it is important that the aerosols are also permanently removed from the room so that they do not move accumulate, “says Matthias Echternach.

“We found significantly smaller distances to the side than to the front, so that the distances could be chosen to be smaller, around 1.5 meters. Here, too, the fresh air is constantly supplied to remove the aerosols from the air,” says Stefan Kniesburges.

Singing with a mask?

Tests with a mouthguard showed that “when singing with surgical masks, the large droplets are completely and the aerosols are partially filtered out, but some of the aerosols are emitted slightly upwards and to the side,” says Kniesburges – because the masks on the Do not seal the sides and nose completely. Singing with a mask, so the discovery, would be an option by reducing the particle emissions, but not really for professional choirs, “because I have to articulate very well and of course need the smallest nuance of sound,” says Echternach. With church or other lay choirs, however, singing with a mask should “prevent a lot”.


More clarity for risk assessment

“The study gives us more clarity in order to be able to better assess the distance rules and climatic conditions in rooms, and we would like to make our findings available to everyone, not least to the decision-makers for new, general requirements,” said Susanne Vongries, manager of the choir of the BR the first partial results of the scientifically unpublished study. “The results will and should not only be helpful to the BR choir. There is a great thirst for knowledge and knowledge in this area in the world of professional choirs in concert and opera as well as in amateur choir singing. The health and safety of not only the members of the choir of the Bavarian Radio , but all choirs and vocal ensembles should come first. ”

For all activities, the choir of the BR is bound to the requirements of the “Hygiene Concept for Cultural Events and Rehearsals” by the Bavarian State Ministries for Health and Care and for Science and Art from June 15, 2020.

Own compositions for singing with mouthguards

While the study was still running, members of the BR choir have developed and implemented many creative alternatives to conventional concert and rehearsal operations within the current possibilities. Small ensembles have developed literature from Lassus to Hindemith and Pärt, and in addition to numerous court concerts in social and charitable institutions, two composition orders have been placed with Rupert Huber and Howard Arman, who composed works for singers with mouthguards. Rupert Huber’s work “U + 1F637” (corresponding to the numerical code for the smiley with a face mask) was created, the melodrama “The Sculptor” comes from Howard Arman’s pen. Both works were produced in the BR studio. U + 1F637 can already be seen and heard on the BR cultural stage (, the composition by Howard Arman will be put online there soon.

Bayerischer Rundfunk reports on the study in the following programs:
Friday, July 3rd: Rundschau, Abendschau, B5 aktuell, radioWelt (Bayern 2), Leporello (BR-CLASSIC), ARD Mittagsmagazin, IQ – Science and Research (Bayern 2)
Saturday, July 4th: Piazza (BR-KLASSIK) as well as in the science magazine “Good to know” at 7:00 p.m. on BR television (available after 5 years in the BR media library)



  • Djeedoo says:

    This will be the end of professional choir singing!!

  • I hope that the Italians will read that study and that it will be possible for Chailly and La Scala to do the Verdi’s Requiem in September.

  • Dennis says:

    The more important thing this misses is that the coronvirus itself is not that serious. IFR in the range of flu, yet we don’t ban singing every season on grounds that they may spread flu do we? This madness must end!

    • Morgan says:

      The comparison with flu is gravely mistaken. Symptoms vary from zero to and quite a few shades in between. Flu can also be deadly of course but not by the same magnitude.
      Some countries have handled it more successfully than others. Let’s hope lessons will be learnt by the time 2nd wave strikes.

    • David says:

      The IFR of coronavirus is what it is now BECAUSE of all the emergency measures that many countries have desperately taken. Even then, it is estimated to be higher than seasonal flu. To argue “this madness must end!” without taking that into consideration is sinfully ignorant and logically fallacious. Oh what’s that? You are still sure that you know better than thousands of experts out there, because they are ALL conspiring for some agenda that everyone except you don’t know about? Good for you! You must feel so powerful spreading nonsensical ideas and contributing to millions of innocent deaths. Real proud of you.

    • Novagerio says:

      Dennis: Wait till it’s your turn to spend three months in a hospital, with one tube down your throat and another one up your *ss, all while you’re slowly choking, then we’ll se if you still call it a “flu”…

    • Antonia Potter says:

      Actually, Dennis, when people say this, it makes me feel they have not followed the news since mid-March! This virus attacks the organs within the body and sometimes in a permanent way, unlike the flu. We have people on permanent kidney dialysis now from this coronavirus. We have young, healthy people in their 30s and 40s who suffered sudden stroke from Covid-19 who are quite possibly permanently unable to ever work again and who need years and years of expensive and long-suffering therapy. We have people with permanent lung damage who’ll need to flee to the hospital at the first sign of a cold because it’ll progress rapidly into pneumonia. It can cause psychosis and a dementia-like syndrome as it attacks the neurological system. My mother survived Covid-19, but her sense of taste is permanently (apparently) altered, such that she barely touches her food now in her longterm care facility and is losing weight, a matter of concern to the facility and consequently the food-distributing workers are scolding her three times a day for not eating. What flu do you know of that can do all of this? Have you done any reading-up at all, or are you simply reciting a motto perpetuated since March by members of a certain group of people who follow a national leader who wanted to “just let Covid wash over the country”?

    • psq says:

      I suggest you volunteer yourself to work in a slaughterhouse. Tönnies in Gütersloh is highly recommended.

    • John says:

      Wow, you aren’t too bright if you still think this exists in the range of the flu. Sit down and shut up, kid.

    • Just saying says:

      Not exactly.
      There are several influenza types and sub-types, some more and some less severe. There is a vaccine (reformulated annually based on the strains predicted to be in circulation); not infallible, but it offers protection. Even so, the WHO estimates 3-5 million annual severe flu cases worldwide, with 300,000-650,000 deaths.

      Even with the extraordinarily restrictive measures introduced in many countries, in six months we have >11 million recorded COVID cases worldwide (increasing rapidly: 10 million reached on 27 June –just a week ago– and 9 million on 21 June, not even a week before). And >500,000 deaths. It’s still there, and there’s no vaccine yet. Infection control is all we have just now, and perhaps includes choral singing.

  • JR says:

    Who did this headline? That is not what the interview says at all. It states most forward issues are under 3 feet but some singers did reach as far as 6 feet forward. He states six feet distance forward should be fine and talks about the importance of returning to singing sooner than later.

  • BillOxford says:

    The study appears to suggest benefits from positioning choral singers in rows at least 1.5, and more probably 2m, apart or erecting partitions between singers. I presume the latter was meant ‘tongue in cheek’, as each singer would need some means of accessing their ‘cubicle’ (complete with a window to allow them to see the conductor)! More seriously, these results do show that choral contributions (amateur and professional) to our musical life are likely to remain on hold for some time to come.