I am hyper-sensitive to voices and it is a good question that you ask.
In general, I don't care for nasal voices. I can't watch a movie with Viggo Mortensen because his voice drives me crazy!!! But really, I am sensitive to voices because I my SE picks up a LOT of high-quality info about people from how they speak, as opposed to what they say or what their natural tone of voice is. In particular, confidence levels, authenticity, feeling and motivation can all be conveyed very simply and quickly from tone of voice. I often rely on it more than facial cues, and I bet a lot of INFJ's use it to help form their creepily accurate predictions of peoples character and behavior.
Some examples:
1. I started work last summer alongside a new co-worker. Within 5 seconds of him walking into the room and introducing himself I got a bad feeling. He spoke overly-loud, theatrically, with a superhuman amount of self-assurance and boisterous friendliness. I didn't trust him at all, he sounded fake and pretentious to me. I complained about him that night to my boyfriend and predicted that he would be a pain in the ass all summer who was going to try and make himself look better at the expense of others. My boyfriend (as always) said I was being negative, judgmental, and unfair; after all, I'd only just met him, how could I know?
He turned out to be super-manipulative, pretentious and obnoxious and constantly tried to maneuver to put himself above us all summer by sucking up to our boss and taking credit for work he didn't do. My boss got so fed up with him she eventually gave him busy work and let him go as soon as she could.
2. My sister is a super-social ESFJ who puts all her self-worth in her friends' and coworkers' opinions of her. I only have to hear her talk for about 3 seconds to tell when she has her "fake voice" on; a voice that is overly-enthusiastic and slightly higher-pitched than normal. When her "fake voice" is on she will agree with whatever you are saying, say what she thinks you want to hear, try to be really agreeable and generally be, well, super-fake. As an INFJ who values sincerity it drives me crazy. When she comes home from work (she waitresses part-time) she is still in her fake people-pleasing mode and it can last a few hours before it fades. And it's def. most obvious from her voice. When she is exaggerating or in a dramatic-storytelling-mode her voice fluctuates up and down wildly and she pauses and lingers over words for effect quite a lot. Vocal cues like this are important indicators of authenticity and motivation as well.
3. I am lucky enough to have a boss who is clinically ADHD and OCD :/. She can reach near-spastic states of excitement and hyperventilation over the organizational state of a filing cabinet holding documents no one looks at from 30 years ago. It is imperative to note the increased intensity and accentuation of her words, an increase in tone or pitch, or faster rate of speaking immediately in order to predict and deflect a possible meltdown before it occurs.
So what I'm trying to say is that it's not necessarily your natural tone of voice but how you use it that matters. Even with Ralph Fiennes's rather nasal voice it is so pleasant to listen to because he uses it soothingly, with gentle smoothness and slight but sincere inflection of emotion that means so much more than just the raw tone/pitch of his voice.
If you have a deep voice I would try to enunciate clearly and avoid mumbling so people can understand you, or they may think you are too shy or unsure of yourself and try to write you off/walk all over you. They may talk over you or not respond to what you just said because they didn't quite catch it and don't want to ask you to repeat yourself. Use more intonation and inflection in your voice to convey meaning (loud/soft or high/low), this will also help your voice carry better over the phone. Show your confidence through your voice, but let it come naturally, don't push it or you will risk sounding artificial and forced which may make people distrust you.