The decision to call the police when domestic violence rears it ugly head is not an easy one to make. Many women feel that they do not want to involve the police in a purely domestic argument. Others consider the impact on the children that a visit from a squad car and several policemen will have on the children's emotional health. The decision to call the police or not must be decided on a case to case basis. Certainly where there is an assault of a spouse or children in your presence, your safety and the children must be protected, so a call to 911 would certainly be indicated.
However where there is a single episode of mild foul languages spoken in the heat of a verbal argument, the answer might be to diffuse the situation yourself by walking away, rather than placing a call for help. Nonetheless, you should never be timid about calling for help when the situation demands such intervention