Monotone or monotonous.
I'm sure that I like your tone of voice. Don't take that tone of voice with me! Your tone of voice belies the sincerity of your statement.
Tone of voice is an effective way of conveying an emotion. However, lots of communication does not even involve the voice. For example, this answer that I am typing has no voice and no tone of voice. If I want to I can include some kind of symbol to stand for a tone of voice. ; )
There are certain voice changing software through which your voice tone will be changed accordingly. One of them would be Voice Changer 6.0 Diamond.
If you have a sharp tone of voice, it can scare people, as can having a soft one calm them I'm always telling my mum to watch her tone, because I read by tone of voice rather than body language
variety in voice tone; the range of expressiveness of the voice.
Tone colour or timbre is that which distinguishes the quality of tone or voice of one instrument or voice from another. For example it is what, with a little practice, people use to distinguish two different instruments even if both are playing notes at the same pitch and loudness. It is the uniqueness of your [the] voice that is gained over a period of practice and training.
To alter the intonation of someone's voice, they would require voice therapy or voice training. This is a non-surgical method of improving or modifying someone's voice tone.
Narrator?
I don't like your tone of voice.
There was a very mean tone in his voice when he spoke.
timbre
When a melody voice part or instrumental part moves from one tone to a tone that is not adjacent, it is said to move by a leap. Leaps can vary in size, and they often create a sense of contrast or excitement in the music. In contrast, moving between adjacent tones is referred to as a step.