I used to be a recruiter after I finished university. It was never a goal of mine to go into a job that involved being on the phone but I kind of fell into it. My boss was supportive because I have a stutter so initially he let me do the calls in the boardroom and not the open plan office. Then after a while I became so focused speaking to the candidates I didn't pay any attention to my stutter or the other recruiters around me. As for the candidates I spoke to, they either didn't mind I stuttered or were pretty rude about it. At first it hits you hard, but if you get your head around that it will only be a small percentage of rude people and your goal is to help your customers, it does become easier to deal with. I think being in a sales was good for me. It built my confidence and desensitized me to less understanding people. Just make sure your boss is understanding Good Luck!