I haven't completely written off the whole 'tonewood' thing, but I'm absolutely certain that I personally wouldn't be able to hear, let alone describe, the tonal differences between ash or alder, or anything else for that matter.
Has anyone ever correctly identified say 5 different body woods in a blind sound test?
From reports I've seen from the recent SE bash, bassists of not inconsiderable experience struggled to identify completely different models of bass in a blind test, let alone what they were made from.