As Toole has explained, he chose to opt out of participating in experiments as a listening subject around the age of 60 because, unlike you, he was aware of the much deeper and more profound impact, of his (normal, age-related) hearing loss, on his ability to assess loudspeaker sound quality in numerous ways that matter.
It's absolutely not about 10-20 kHz.
Of course, unlike Jones, Toole's deep experience in listening to flaws in loudspeakers is supplemented by a deep knowledge of human psychoacoustics. Plus, he correlated his knowledge of the specifics of age related decline with his own measured loss in ability to discern loudspeaker flaws in controlled experiments.
So there is every reason (and nothing to do with 'my being so confident', as some are so quick to assert and others equally quick to 'like') to conclude that, even if Jones has been conducting controlled listening tests for the past 20 years that they would mislead him. Add to this the high likelihood that he is doing it sighted, and it amounts to nothing less than a mistake.