Spectral emphasis as a stress cue in the Latinamerican Spanish

Abstract

Several studies have reported that spectral emphasis is a reliable correlate of stress, e.g., [Sluijter and van Heuven, J. Acoust. Soc. Am. 100(4), 2471–2485] that is to say, harmonics situated above 0.5 kHz present more prominence in a stressed vowel. The spectral balance or spectral emphasis was then examined as a cue related to loudness or intensity. The present work analyzes the relationship between the descripted phenomenon and the vowel pitch, in order to relate the contribution of higher harmonics with the probable perceived pitch and evaluate their actual weight. The virtual pitch theory [Terhardt, Stoll and Seewann, J. Acoust. Soc. Am. 71(3), 679–688] provides a way to understand this relationship. To achieve this purpose a speech production study was done with native latino-american spanish speakers. The corpus consisted of minimal stress pairs of bi and trisyllabic lexical items with and without stress in a carrier sentence. Analysis was developed in two steps. In the first step were obtained the values in frequency and sound pressure level in decibels for a frame of each harmonics through a tracker algorithm. In a second step, the virtual and spectral pitch was extracted from the first step data, in accordance with pitch virtual theory. Results show an increase of weight of spectral pitch in frequences superior to 0.5 kHz.