Accents can be conveyed by F0 peaks timed either 'early', 'medially' or 'late' with respect to the onset of the stressed vowel. Perception tests involving single-peaked utterances have shown that listeners can differentiate these variants and attribute them distinctive intonational meanings. Production tests comprising simulated interviews have confirmed that speakers use intonation to convey such differences in meaning in single-peaked utterances when their linguistic means of expression are limited through the test situation.
Bibliographic reference. Gartenberg, R. D. / Hertrich, Ingo (1989): "Speaker responses to F0 manipulations in partly controlled simulated dialogues", In EUROSPEECH-1989, 2112.