Thanks I figured the bottle sucking in was not something amazing. My frequency detector works with a sine wave but not with the human voice. Here is a plot of the human voice. Perhaps I should be counting peaks not zero crossings. https://msu.edu/course/asc/232/study_guides/F0_and_Glottal_Pulse_Period.html
I was at a bar with a friend. He said are you going to watch the baseball Superbowl? NO! This hockey game. No! That football game. NO! I said that I have more important thing to do. I will; however, watch the show about the Neanderthals on PBS. He said, your retired, what could be more important than the games? Daah! Frank
