How does the hearsay rule apply to prior statements of a testifying witness?

In general, the hearsay rule prohibits the admission into evidence of out-of-court statements to prove the truth of the matter stated. This rule applies even to prior statements of a testifying witness that are consistent with the witness's testimony. As the majority explains (majority op. at 513, 934 N.Y.S.2d at 6667, 958 N.E.2d at 10001), the reason generally given for the exclusion of prior consistent statements is that an untrustworthy statement is not made more trustworthy by repetition ( People v. McClean, 69 N.Y.2d 426, 428, 515 N.Y.S.2d 428, 508 N.E.2d 140 [1987] ). While this is undoubtedly true, it is also true that jurors are smart enough to know it, and thus in most cases so-called bolstering testimony does little harm. Indeed, the most cogent objection to it seems to be that it is generally a waste of timethat it hinders trial efficiency, as a law review article quoted by the majority suggests (majority op. at 513, 934 N.Y.S.2d at 67, 958 N.E.2d at 101).