Many people who know Tollers have heard the "Scream".   Do all Tollers scream?  No, they don't, but many do.  The scream will be heard when the Toller is very excited - chasing a squirrel for example (as seen in the video below).  Or when being held back from a retrieve.  They CAN be taught not to scream in the field so don't let the scream deter you from getting a Toller to hunt with or run in field tests.