Ton, timbre and intelligence are important in the voice. Goodwill — the best tone for any conversation. If the timbre of your voice is deaf — speak louder. You will achieve the intelligence of the voice by training: first read aloud some text, write it on a recorder and listen. Repeat the exercise several times. And the last: smile! The interlocutor will not see your smile, but will certainly feel. In any case, she will create a good mood for you!