911 calls can range from vital evidence to worthless. How important they are depends on a lot of things. Your attorney would be in the best position here to advise you on its value or lack thereof.
I agree with my colleague, also you should know that it really doesn't matter what type of case it is. If the state/city believes the tape would add value to the trial, it would likely be used. Unless, there is a reason for the court to suppress it.
Only your attorney can tell you specifically if it is likely to be used and why or why not.
If you do not have an attorney, you should hire one or be screened for a public defender in your area.
As the previous attorneys stated, it depends on the case. Often in DV cases 911 calls can be an important piece of evidence, especially where the alleged victim has changed their story or doesn't appear for trial. However, in some cases, a 911 call is totally meaningless and no one would seek to use it.
Whether it is admissible or not is a complicated legal issue. In many cases, a 911 call is inadmissible because it is hearsay and a defendant has a constitutional right to confront his/her accuser. There are exceptions to this rule and some 911 calls are not considered hearsay.
An experienced criminal defense attorney can evaluate a case and all evidence, inlcuding any 911 call to determine who helpful/harmful a 911 call may be and how likely it is that a Judge would rule that is admissible at trial.