How would you describe someone's speaking voice?

When describing the way a character speaks, I always get stuck on how to describe how they are speaking. I don't want to focus too much on it, just as a way of distinguishing between characters in addition to dialogue.

Anyone have any tips? For example, I want to describe how one of my antagonists speaks. He's a pretty slimy guy, patronises almost everyone and is often quite insulting because of the way he talks down to everyone. How can I describe the way he speaks in a simple way, just as a passing comment? I know all the typical ways such as with a hoarse voice, for example, but I cannot think of a way to describe him in particular. Thanks in advance for any help and suggestions!

You don't always have to describe a person's voice, unless it's relevant to the situation. For example, if a character is threatening or angry the tone of their voice would be low, and if they're happy or excited their tone would be a little higher. Or if they have a lisp or something you would mention that. Other than that, I'd suggest leaving the rest up to your readers. Your readers will often create their own images of your story characters in their heads, and they will attach their own voices to that character however they think fits. Sometimes your readers do the work for you when visualizing a character, so that means you can focus more on important things, like the character's personality.

When describing how a character talks, don't use narrative. Let his own dialogue define the way he speaks. If he's condescending or uptight his words will show it more than any amount of narrating can.