toned voice. However, for most of the shows  run, he spoke in a deeper tone. Both tones appear in the episode,  "No help wanted"; as Fred and Barney debate about Barney  repossessing Freds TV because he owes payments on it, Barney hides  in Freds TV. When Fred turns it on, Barney talks in the deeper  voice, but goes back to the nasal quality as Fred tries shaking him  out.