What is the test for establishing identity of a party to a telephone conversation?

'(I)dentity of a party to a telephone conversation may be established by proof of recognition of his voice or by other evidence which satisfactorily indicates identity of the individual.' (People v. Nails, 214 Cal.App.2d 689, 692, 29 Cal.Rptr. 671, 673.)

The contents of the telephone conversation itself may be considered in relation to other evidence to establish the identity of the speaker. (People v. Nails, Supra, p. 693, 29 Cal.Rptr. 671; People v. McGaughran, 197 Cal.App.2d 6, 16, 17 Cal.Rptr. 121.)