Speech Prosody 2008
Vowel opening and spectral emphasis are investigated as possible acoustic correlates of secondary stress in Brazilian Portuguese. F1 and energy difference between frequency bands were measured for vowel /a/ in five- and six-syllable stress groups. Results for F1 indicate greater opening for vowels in initial and stressed positions. As for the spectral feature, relative emphasis in bands B2 (0.5 to 1 kHz) and B4 (2 to 4 kHz) has some relevance to phrase stress signaling, but not to secondary stress if it is to be equated to binary alternations.
Bibliographic reference. Arantes, Pablo / Barbosa, Plinio A. (2008): "F1 and spectral correlates of secondary stress in brazilian portuguese", In SP-2008, 559-562.