That's because the particles that carry the virus get diffused by circulating air, when people are gathered indoors in tight spaces without good ventilation that increases the likelihood of spread.
This is because warm air doesn't rise in space, so sleeping astronauts in poorly ventilated sections can wake up gasping for air, surrounded by an invisible bubble of their own exhaled carbon dioxide.
If you're in a poorly ventilated room for a long period of time and someone's positive, there can be transmission inside those rooms. Eating together, very high-risk activity.
They were given fluorescent hand gel so scientists could see which surfaces were touched most often, and smoke was pumped to track how ventilation affects the spread of the virus.
The ear buds gently seal the ear for rich bass and clear highs, and the spatial vent underneath reduces that plugged-ear feeling and lets through just the right amount of environmental sound.