'Metrical' factors in the scaling of sentence-initial accent peaks

Past studies of declination make contradictory claims about the relationship between the length of an utterance and the height of its first accent peak (P1): Some find a large increase in P1 with increased length, others find little or no increase. A possible explanation for this contradiction is that large increases in P1 occur when the first major constituent of the sentence increases from one accented item to more than one, but not as a function of overall length alone. In an experiment, 1 of 2 speakers behaved in the way just outlined; data from the 2nd speaker supported the more general hypothesis that 'metrical' constituent structure is relevant to P1.