"The voluntary consent of the human subject is essential," they wrote.

"No reasonable officer would have understood the occupants' silence to be a voluntary consent to search the rest of the apartment."

The voluntary consent of the human subject is absolutely essential.

Any undertaking that involves more than one man, requires the voluntary consent of every participant.

We do not collect this type of information without the voluntary consent of the site visitor.

Experiments on humans have been put under some controls, namely informed and voluntary consent.

And we have to pay attention to the different standards of voluntary consent that operated at that time.

To be ethical, researchers must obtain the full and voluntary informed consent of participating human subjects.

And so it was her voluntary consent to the divine plan that allowed it to go into motion.

"How can potential donors give voluntary informed consent when we don't have enough information to tell them what they need to know?"