Adults with history of recreational cannabis use have altered speech production

Scooby-Doo

The title seems like a stretch since they then go on to say,

"Audio samples were analysed objectively using acoustic analysis for measures of timing, vocal control, and quality. Subtle differences in speech timing, vocal effort, and voice quality may exist between cannabis and control groups, however data remain equivocal."

"After controlling for lifetime alcohol and tobacco use and applying a false discovery rate, only spectral tilt (vocal effort and intensity) differed between groups and appeared to change in line with duration of abstinence from cannabis use"

Basically no acoustical difference, except in perceived effort. You'd get the same intensity out of a group of tired people too, but that oddly doesn't seem to have been compared in the study

Could it have anything to do with subcultural differences among cannabis users and not deleterious physical effects of consumption?

> Basically no acoustical difference, except in perceived effort.

On the data points measured. It's easy to observe things like "heavy cannabis users tend to have flat affect," but very difficult to translate "flat affect" into something measurable.

Look at the way that Alex Grey or Terence McKenna talk. There is clearly something going on there, regardless of our ability to measure it.

Given they only had 31 subjects, and the group with cannabis use without cannabis use differed drastically in alcohol and tobacco consumption, I think one should take these results with some degree of caution.