What factors will the court consider in determining the admissibility of an expert opinion on voice identification?

As with eyewitness identification, some factors pertaining to voice identification might not be widely known or may be counterintuitive. We need not decide whether expert testimony may be proper as to these factors. (Cf. People v. McDonald (1984) 37 Cal.3d 351, 367-368, 208 Cal.Rptr. 236, 690 P.2d 709.) However, it is a matter of common experience that the ability to remember a perceptive experience diminishes over time. It is also generally known that voices may sound slightly different through different media. Expert opinion on these matters was not required to determine the admissibility of the voice identification under the totality of the circumstances. Especially given the fact that the witness was not available on the day of the hearing, the trial court did not abuse its discretion.

[3 Cal.4th 138] 3. Hearing on Brigges's Identification