I had an answering machine message that went like this.
My machine comes on..
I have said ~ "Hello"
The person usually responds "Hi or Hello", then starts talking.
I've waited a few seconds and said, "Could you please speak up a little, I can't hear you."
Most people raised their voices and started repeating their message.
I waited a few more seconds and said, "Sorry about this, but could you PLEASE talk louder. I just can't hear you."
The caller, a little frustrated starts to repeat their message again talking much louder than previously.
Again I have recorded, "Hey, I still can't quite hear you. You have to speak LOUDER!"
By now, the caller is upset and would repeat their message again, almost at a yelling level now. If they haven't hung up due to frustration, they then get the message in a jovial tone, "OK OK! You don't have to yell. It's only an answering machine anyway. Just leave your name and number and I'll get back to you. Thanks for calling."
It kept telemarketers from bugging me but nearly cost me a few good friends and teed off a lot of others, but I thought it was funny and clever.
I don't suffer from insanity, I enjoy every minute of it.