I remember when my MIL first got her Bluetooth. We were at Walmart one day and we both went in our own direction. A little while went by and I heard her "talking" but in a VERY loud voice. She's a loud talker to begin with, but she was YELLING!!!
I finally caught up with her and asked why she was screaming so loud. She said she was talking on her "Blue TUBE" and SHE couldn't hear the person on the other end of the phone, so she had to yell....
She's had the thing for quite a while now but still is convinced it's called a Bluetube and not a Bluetooth.