The big news item in the United States recently is that it was found that Beyonce didn’t really sing live during the presidential inauguration, but just mouthed the words. This news only hit Canada and the rest of the world now since it’s so cold outside that news (and the speed of sound which is a function of temperature) is so slow up here.
Well, I don’t blame Beyonce one bit. I would also probably lip synch if I was invited to sing the anthem in an outdoor venue, which would never really happen since I can’t carry a tune at all. I can’t even sing Happy Birthday- I may (or may not) find the key that the group is singing in by the very last line. And let’s not forget, to try to make amends, she sang live at the Super Bowl … or did she?
Anyone who sings outside without reflective surfaces will immediately notice that there is well… no reflection. It’s amazing how important reflection off walls, ceilings, and floors is to the monitoring of our own voice. In addition, the crowd noise can be a very effective masker of what little you can hear of your own voice.
Beyonce had probably learned in her first year acoustics class about the optimal ratio of early and late reflections—both of which would be missing in a large reflectionless (anechoic) stadium. This is actually important evidence that she took a first year audiology class in acoustics. How else would she know that it was safer to lip sync the words?
Reverberation is a really neat topic and is full of pitfalls- more is good, but not too much more; less can also be good, but not too little. It is really a topic of balance. One measure that is commonly used is the “Reverberation Time” or RT. This is the time in seconds that a signal takes to drop off in sound level to a certain specified level. A commonly used measure is RT60, which is the time it takes for a sound to be reduced to a level that is 60 decibels lower than the initial sound. An underground car garage has an RT60 of about 4-5 seconds- if you yell in an underground car garage, you will still clearly hear your echo several seconds later.
A library has a reverberation time of about half av second- the carpeted floor and row upon row of sound-absorbing books minimize the reflections and echoes to a point that it almost sounds “acoustically dead”. An ideal time for speech clarity is just short of 1 second (0.9 seconds), but different types of music may require different RT60s, and even different types of rooms with differing acoustical treatments may require different RT60s.
Organ music requires an RT60 of 2.5-5.0 seconds and this is related to the longer lasting notes of organ music- blurring some sounds together can be a good thing. I am not sure, however, which came first- the beautiful Baroque cathedrals with the arching high ceilings or the music that was meant to be played in these cavernous rooms. If medieval or romance architecture were more like the modern day architecture I suspect that the organ would never have found a foothold in music (except, of course, for the 1960s rock sound).
It’s amazing to realize that Beyonce knew all of this when she agreed to sing at the Inauguration, but since Beyonce is a probably a closet audiologist, maybe it’s not so surprising after all. How else would she have known about RT60 and the need to lip synch?