To clarify this even further, as someone who professionally plays an instrument that is traditionally placed at the back of an orchestra, you absolutely cannot play by ear: you MUST play by watching a combination of the stick in the conductor’s hand and the bow of the first violinist and cellist at the front. If you play what sounds in sync to you, the conductor and audience will hear you too late; the round trip from the front to the back of a stage, plus the sound traveling through the brass tubes of your instrument, plus the trip from the rear of the stage to the first row of the audience simply takes so long that it will sound noticeably wrong. The same is true for the far sides of an orchestra pit underneath the stage of a musical or opera. It only takes 20 meters/yards to become an issue.
It is generally said that the lowest threshold for people to perceive time delays is around 10-15ms.
Speed of sounds is roughly 343 meters per second. Which means translates we can sense the delay difference of about 4-8 meters or so.
Which 100% corresponds with what you are saying. 20 meters is a 58ms-ish delay.
A 200ms is about 70 meters. Which would be like having conversation between people using one of those accidental sound projection features that sometimes happens with large open buildings like sports stadiums.
people talk in a cadence of around 100-200 words per minute. I guess we could say that is 300-600 syllables per minute. So that is about 200-100ms per syllable.
