I'm going to pretend to be deaf for a tip
What are going to gain by pretending to be deaf?
To be an excellent actor since I can hear everything well.
Lying to people about a disability in order to get money is very dishonest. Not only is it unethical and mean, but could possibly be considered illegal as well.  I hope you agree not to actually do this.
So what? I'm only doing it for a dollar.
It really isn't okay to be so dishonest, even if just for a small amount of money.  Frankly, it's quite disrespectful to people who really have hearing impairments.  I'm sure that if you do your job well, people will reward you.