I understand that concerning their field of expertise (voice anylization in your example).
But when it comes to discerning whether or not a person is telling the truth and whether their statements are supported by the facts.....who would be a more qualified “expert” than a veteran police detective who’s job it is to do just that?
Like Bernardo de la Rionda?
Judging the veracity of a witness is the jury's job. Laymen are qualified to judge cedibility. They don;t need an expert to tell them who is telling the truth.