What is the effect of Miranda warnings on a defendant's confession?

We now turn to defendant's second contention, i.e., that other circumstances surrounding the postarrest interviews rendered his confession involuntary despite the fact that Miranda warnings were given. In determining whether or not a defendant's confession is voluntary, the totality of circumstances must be considered. (People v. Weaver, supra, 26 Cal.4th at p. 920, 111 Cal.Rptr.2d 2, 29 P.3d 103.) On appeal, "we independently examine the record, but, to the extent the facts conflict, we accept the version favorable to the People if supported by substantial evidence." (Id. at p. 921, 111 Cal. Rptr.2d 2, 29 P.3d 103.)