�y��vlog

But, he said "the range of Crudup's vocal skill is such that you can imagine the peaks and dips of a spirometer graph purely from his performance".

It’s often done using a spirometer - a device with a mouthpiece connected to a small machine.

It’s often done using a spirometer — a device with a mouthpiece connected to a small machine.

He picks up a spirometer, a device that measures lung capacity, and takes a deep breath — though not as deep as he'd like.

For example, spirometers, routinely used devices that measure lung capacity, still have correction factors that automatically assume smaller lung capacity in Black and Asian individuals.