Do use the right tone of voice; normal tone for commands, high tone for praise and firm tone to address any unwanted behavior. (barkbusters.com)
Talk in a matter - of - fact, calm and normal tone of voice. (baywoof.com)
Under way, with the top up, the car passed its third important test with high marks: You can hear the radio without straining, and you can hold a conversation at normal tones. (articles.orlandosentinel.com)