In the approach used by the "Longman Pronunciation Dictionary", Wells claims that consonants syllabify with the preceding rather than following vowel when the preceding vowel is the nucleus of a more salient syllable, with stressed syllables being the most salient, reduced syllables the least, and full unstressed vowels ("secondary stress") intermediate. But there are lexical differences as well, frequently but not exclusively with compound words. For example, in "dolphin" and "selfish," Wells argues that the stressed syllable ends in , but in "shellfish," the belongs with the following syllable: → , but → , where the is a little longer and the is not reduced. Similarly, in "toe-strap" Wells argues that the second is a full plosive, as usual in syllable onset, whereas in "toast-rack" the second is in many dialects reduced to the unreleased allophone it takes in syllable codas, or even elided: → ; likewise "nitrate" → with a voiceless (and for some people an affricated "tr" as in "tree"), vs "night-rate" → with a voiced . Cues of syllable boundaries include aspiration of syllable onsets and (in the US) flapping of coda "(a tease" → vs. "at ease" → ), epenthetic stops like in syllable codas ("fence" → but "inside" → ), and r-colored vowels when the is in the coda vs. labialization when it is in the onset "(key-ring" → but "fearing" → ).