5 1251 sum typewriter canadian raising raising ai voiceless stops uncommon various parts eastern us canada simply someone cant hear difference nt mean nt dawn seed j k chamber canadian raising canadian journal linguistics 18 1973 better yet timothy vance canadian raising dialects northern us american speech 62 1987 tell generally someone else word boundaries come play ice scream scream quite different normal speed quite without raising sounds like quiet though different issue dialect groups note say eh