Monday, May 18, 2020

How Speaking Can Spread the Virus

When Prime Minister Justin Trudeau was asked about the benefits of wearing face masks to stop the spread of the Coronavirus, he said that “they are helpful in that they protect others from you “breathing or speaking moistly on them.”

The word ‘moistly’ caused a universal uproar. Comedians had a field day as usual, but Trudeau was actually giving an appropriate and descriptive name to one of the major avenues of infection, which is our own speech.

One of the reasons COVID-19 spreads so quickly is that it is transmitted from people who are asymptomatic. But if they don’t sneeze or cough on you, how are they actually infecting you?

Research is now showing that coughing and sneezing are small potatoes compared to the amount of aerosols people emit while they speak. Coughing and sneezing are like brief but potent rain showers, whereas speaking is a day long drizzle, with smaller drop sizes that can penetrate deeper into the lungs of the unfortunate recipient. They also remain airborne longer, since they are smaller.

It is not just speaking that releases more particles than coughing or sneezing. A person who decides to declare their love by bursting into a serenade, is actually emitting 6 times more airborne droplets than if they were merely reciting a poem.

If things weren’t bad enough, it turns out that people with loud voices emit an inordinate amount of particles. Not only are they a danger to your ear drums but they actually are equivalent to the fire breathers of yore.

Although the louder you speak the more particles you emit, the study also found that certain units of speech generate more aerosols than others. For example, the "E" sound in "need" produces more particles than the "A" in "saw."

The ‘phonemes’ (the basic units of speech) that require the use of the vocal chords, like ‘b’ and ‘d’, yield more aerosol particles than the voiceless ones, like ‘p’ and ‘t’. ‘Plosives’ - the sounds that come out like a bullet (‘b’and ‘d’) yield more particles than sounds that come out like a fizz (f, sh). In general, voiced plosives (bad, dad, good) and nasal sounds (mama, nose) are the bad guys and voiceless fricatives are not so bad.

Vowels are worse emitters than consonants. Does that mean that a language like Hawaiian, which uses vowels extremely generously, spreads the virus more than English? The Hawaiian reef trigger fish is called ‘Humuhumunukunukuapua`a’.

What about languages that have long words? Doesn’t that mean more vowels, more talking and more infecting. ‘I am here’ (3 syllables) in Japanese is ‘Watashi wa koko ni imasu’ (9 syllables).

This ties into something called the speech information rate’, i.e. the speed at which a language conveys information. Some languages are better at it than others, in fact here is a list:

As you can see, English comes out on top, but languages that are less information dense, like Spanish or Japanese, are spoken faster, so it evens out.

Did I just opened a can of worms? As if we didn’t have enough –isms in the world. We don’t need to add ‘languageism’ to the list.

Still, it makes sense to study speech in the context of the Coronavirus. After all speaking is directly related to the lungs. Studying cross-cultural differences on how people walk would not serve much purpose right now.

Everybody knows that the meaning of words influences human behavior. But the words of a Guru, the Bible, the Koran, none of it matters these days. It is the sound of words, whether you sing them, shout them or whisper them, that we need to worry about. The children’s rhyme ‘Sticks and stones may break my bones, but words will never break me’ definitely needs revision. leave comment here

Why speaking 'moistly' could be partly to blame for the rapid spread of COVID-19
Effect of voicing and articulation manner on aerosol particle emission during human speech
Visualizing Speech-Generated Oral Fluid Droplets with Laser Light Scattering
Talking Can Generate Coronavirus Droplets That Linger Up to 14 Minutes