The question is not whether people can infer some information from their environment using sound. That is very clearly the case. As most people will know from personal experience by detecting the presence or absence of nearby walls due to the presence or absence of ambient echo.

The question is whether the claims of "expert" echo locators can be verified and whether it would be a worthwhile pursuit to standardize and teach this technique to blind and low vision persons.

I could attempt to learn this technique but I have enough vision that I'm generally not in need of it especially with the application of current compensations. I could attempt to learn it for personal verification reasons but I would then be just another anecdote and that's not really what I consider suitable evidence for validation.