In some analyses, then, the concept of lexical stress may become conflated with that of vowel reduction. An approach which attempts to separate these two is provided by Peter Ladefoged, who states that it is possible to describe English with only one degree of stress, as long as unstressed syllables are phonemically distinguished for vowel reduction. In this approach, the distinction between primary and secondary stress is regarded as a phonetic or prosodic detail rather than a phonemic feature – primary stress is seen as an example of the predictable "tonic" stress that falls on the "final" stressed syllable of a prosodic unit. For more details of this analysis, see Stress and vowel reduction in English.