An Acoustic Phonetic Portfolio of a Portuguese-Accented English Idiolect

This paper is an acoustic phonetic analysis of English consonants, vowels, and suprasegmentals produced by the second author. It was carried out in the spring of 2015 in the first author’s acoustic phonetics class. Students recorded themselves at the beginning of the semester and analyzed their speech acoustically throughout the semester. They created acoustic portfolios that consisted in 10 individual projects. The main objective of the course is to initiate students to the techniques of acoustic phonetic measurements within the Speech Intelligibility framework, which espouses the view that intelligibility can be measured acoustically. This portfolio was selected out of many for two reasons. First, the second author demonstrated proficiency in the acoustic phonetic measurement techniques. Secondly, her data gives us a window into some aspects of the acoustic phonetic characteristics of a Brazilian Portuguese-accented English idiolect. The second author is a female from the state of Maranhão, more precisely from the city of São Luís. She began learning English when she was 11 years old in Middle school. Her English teachers were all native speakers of Brazilian Portuguese. She spent six months in Canada before moving to Minnesota. She had been living in the US for two and a half years at the time of these recordings and analyses. 1.0 Introduction This portfolio contains the following projects: 1) two narrow phonetic transcriptions of an elicitation passage, 2) an acoustic phonetic analysis of initial vowel glottalization, 3) an acoustic vowel space, 4) an analysis of Voice Onset Time (VOT), 5) an acoustic study of consonant frication, 6) an acoustic phonetic analysis of nasal consonants, 7) an acoustic phonetic study of approximants, 9) an acoustic phonetic study of lexical stress of ordinary disyllabic words, and 10) an acoustic phonetic study of lexical stress of disyllabic homographic words. The measurements from these analyses are interpreted from the standpoint of the Speech Intelligibility framework pioneered by Physicist Harvey Fletcher and his team at the Bell Research Laboratories. Their goal was to investigate the physical characteristics that may impede intelligibility in telephone conversations. Their endeavors led to breakthroughs, which Yost (2015:49) describes as follows: Fletcher oversaw a litany of psychoacoustic research achievements unmatched in the history of the field, which included measurements of the auditory thresholds (leading to the modern-day audiogram, the gold standard for evaluating hearing loss), intensity discrimination, frequency discrimination, tone-on-tone masking, tone-in-noise masking, the critical band, the phone scale of loudness, and the articulation index. Two of the more important psychoacoustic contributions of the Bell Laboratories years are the critical-band and equal-loudness contours. 1 The 8 project consisted in teaching students to convert the absolute intensity values of segments to a logarithmic scale for the purposes of verifying the Sonority Sequencing Principle (SSP). This project is not included in this report. 1 Koffi and Ribeiro: Acoustic Phonetic Portfolio of a Portuguese-Accented English Idiolect Published by theRepository at St. Cloud State, 2016 Linguistic Portfolios – Volume 5, 2016, page