What is the test for waiving the voir dire in a sexual assault case?

Dickson C.J. said in Park v. The Queen (1981), 1981 CanLII 56 (SCC), 59 C.C.C. (2d) 385 at p. 393: Although no particular form of words is necessary the waiver must be express. Silence or mere lack of objection does not constitute a lawful waiver. The question is - - does the accused indeed waive the requirement of a voir dire and admit that the statement is voluntary and admissible in evidence? If that question can be answered in the affirmative I cannot think that any further procedural safeguards are necessary to protect the rights of an accused person.