In technical terms, the part of the sentence that identifies the speaker of a line of dialog is called a dialog tag, or dialog attribution. I’ve read manuscripts in which characters have sneezed, wheezed, and choked lines of dialog. When a writer uses verbs like this in dialog attribution, she smothers the voice of her characters, and shifts the emphasis from the dialog to the author’s interpretation of the dialog...
Think of it this way. In a well written scene, the reader is actively imagining the characters move and speak. The reader reads the line of dialog and hears it in her head as she reads. If the dialog exchange is logically structured, the reader usually knows who is speaking before reaching the dialog tag. Imagine what happens when the author intrudes at the end to tell the reader how the character spoke the line, and it conflicts with how the reader heard it, or repeats the obvious. This creates dissonance, the reader objecting to the author's insistence that the line be read a particular way. Overly descriptive dialog tags commit a literary sin similar to the use of adverbs in dialog attribution (he spat hotly); they force the author's interpretation on the reader. The reader might resent such a writer.
Literary characters are like actors. They need conscious and unconscious motivations, direction, and space to create. My role as a writer is to direct the characters, devising conflicting motivations that will help the scene they play escalate in tension, and then to give them space to create. On the stage and film set, a good actor will despise the director who tries to force her into saying a line a certain way. A director who gives specific line readings treats his actors like puppets. A writer who uses overly active verbs and adverbs in dialog attribution forces her interpretation of the scene not just on the reader, but on the character as well. This can result in wooden, lifeless characters, mere mouthpieces for the bossy writer.
Every now and then, a dialog tag begs for an active verb or a rich adverb. Save these instances for when they matter. Sometimes the writer might want to contradict the reader, or to emphasize for dramatic effect how a line is delivered. For most dialog exchanges, the emphasis might best remain on the dialog itself, rather than the author’s interpretation of the dialog. To put the emphasis on the dialog, use plain verbs such as said, whispered, and shouted. Step back and let the characters speak for themselves. You might be surprised how much they have to say, and how much more crisply they say it.