The resonance of the cello 'closest to human voice'

"Popular wisdom and many cellists (including Cello Fury, 2CELLOs and famous classical artists such as Steven Isserlis and Yo-Yo Ma) also suggest that the resonance of the cello is the closest instrumental equivalent to the human voice."

The article in the Pittsburgh Post-Gazette goes on to describe a study in Musicae Scientae which suggested that the the claim is "inherently unprovable", they suggest that it is "linked to psychological phenomenon rather than actual instrumental mechanics".