The general vocabulary for describing timbre is limited and highly imprecise. There are many ways in which a passage of music could be perceived as "bright" or

The general vocabulary for describing timbre is limited and highly imprecise. There are many ways in which a passage of music could be perceived as "bright" or "dark", even if the timbre is identical. It might just be a translation issue, but the paper gives me the strong impression that the authors do not actually understand timbre.