It may have been 'watch your tone' - this means your tone of voice, such as whether you sound angry or argumentative. It is said by a superior to someone who is speaking to them in a manner which they do not think is acceptable. It does not mean the sort of tones that are heard in languages such as Chinese. It is more about a bad attitude that is expressed in the way the person speaks.

In drama , I think that is warning you watch your voice and don't make a racket . Do you think？