Nah. "Tichy" is not existing word in Polish. Hovever, there is very similar word "cichy" that means "silent", low volume sound. Probably not accidental.
Lem actually mentions that at some point... while I don't have my copy of Peace on Earth with me, there's that scene where Tichy's picking out postcards and drawing sketches on them. He draws a mouse on a postcard with an owl and says something along the lines of "And how does a mouse behave around an owl? It is quiet, quiet as a mouse." and then comments on his name.
Nah. "Tichy" is not existing word in Polish. Hovever, there is very similar word "cichy" that means "silent", low volume sound. Probably not accidental.