Is a trial counsel prejudiced the defense by failing to object to inadmissible evidence?

Appellant contends that his trial counsel prejudiced the defense by failing to object to several items of inadmissible evidence. He acknowledges that it is his burden to affirmatively show that the omissions of counsel involved a critical issue and that they cannot be explained on the basis of any knowledegable choice of tactics. (People v. Stratton, supra, 205 Cal.App.3d at pp. 93-94.) Nevertheless, he cites several examples of his trial counsel's failure to object to evidence and his cross-examination of prosecution witnesses that he contends reinforced the prosecution's case.