I didn't quite decide the specifics, but the range would be between 1 to 7 years ago. Because the last time some of the PCs were at the Carnival (per the Lost Items hook) was 8 years ago. I would think that time range is when Kettlesteam decided to take matters into her own hands, and thus, take Candlefoot's voice.
Oof. Up until that point in your post that has Tsak recognise Palasha's song, I simply thought Candlefoot had only been without his voice for the last few days. The fact that it has been one year at mininum is... disturbing, to say the least.

