[SoX-users] Is it possible to smoot variation on parameters for filters in SoX?

[Гуляев Г. <gos...@ya...>]

Good day!
Please, help me with that question:
I'm use SoX for mixing audio tracks and i'm often need to do smooth volume  
change, or smooth speed change etc...
I don't know is it possible automatically do this with SoX? Now I need to  
do such tasks in audacity, but i want SoX.
I found "dirty" solution is: script cut audio track to samples in 0.5s and  
for each apply SoX with variable parameter in script. After that all  
pieces is concatenating in resulting track. But after that procedure  
appears various snaps in track.

Thank you!