An Acoustic Study of the Tongue Root Contrast in Degema Vowels

Abstract

Degema is an Edoid language of Nigeria whose ten vowels are organized phonologically into two sets of five. The two sets are thought to be differentiated by the degree of tongue root advancing. This paper examines the acoustic nature of these vowels as represented in field recordings of six speakers. The most consistent acoustic correlate of the tongue root contrast was found to be the first formant frequency which consistently distinguishes four of the five vowel pairs, the exception being the two low vowels. Three of the five pairs could also be distinguished by F₂, though the direction of the difference was not consistent. Additionally, a comparison of corresponding advanced and retracted vowels using a normalized measure of relative formant intensity demonstrated that this correlate could also distinguish them in general, but only operated reliably in two of the five vowel pairs. The pair of low vowels could not be distinguished from each other by any of these measures. Finally, a perceptual study was conducted which demonstrates that Degema speakers do not classify their vowels very well using formant frequencies as the sole acoustic variable; only the two pairs of mid vowels were reliably singled out by native listeners from an array of synthesized vowels.

ATR Harmony in African Languages

“…Thus, all else equal, a [+ATR] vowel will have lower F 1 than its [−ATR] counterpart. In instrumental acoustic studies (e.g., Lindau and Ladefoged 1986;Demolin 1992;Hess 1992;Maddieson and Gordon 1996;Fulop et al 1998;Casali 2002;Guion et al 2004;Local and Lodge 2004;Calamai & Bertinetto 2005;Abdul-Rahman 2006, Akpanglo-Nartey 2006Anderson 2006Anderson /2007Gbedble 2006) of ATR harmony languages, F 1 has consistently been found to be a very robust cue for distinguishing [+ATR] vowels from their [−ATR] counterparts (e.g., [i] has a lower F 1 than [I], [e] has a lower F 1 than [E], etc.). F 1 is also the primary acoustic correlate of tongue height.…”

Revisiting acoustic correlates of pharyngealization in Jordanian and Moroccan Arabic: Implications for formal representations

“…The observed differences (through β and percent correct values) are small compared to formant based measures, and these high frequency components seem to act as secondary correlates. More specifically, a lower A1*-A2* is correlated with a constriction closer to the tongue root (i.e., mid to lower pharynx) as is the case in languages with [-atr] vowel specification (see e.g., Aralova et al, 2011;Fulop et al, 1998;Guion et al, 2004;Kang & Ko, 2012, among others). This suggests that in MA, a lower constriction location for pharyngealization may be in operation, although a nonsignificantly lowered A1*-A2* at the onset in JA is obtained.…”

“…This should not be seen as an indication of an increased noise, as an increased noise as seen in breathy voice and/or glottal opening will increase spectral tilt further and H1-A3 will be much higher (for more detail, see e.g., Hanson & Chuang, 1999;Hanson et al, 2001;Klatt & Klatt, 1990;Stevens, 1998). Moving to the higher frequencies, the amplitude difference A1-A2 is directly related to phonation types, and thus a creaky/tense voice tends to have lower A1-A2 (Aralova et al, 2011;Fulop et al, 1998;Guion et al, 2004;Kang & Ko, 2012). And finally, constricting the epilarynx on its own or through retraction of the tongue root leads to an increase in the energy of the harmonics above F1.…”

Tense-Lax Vowel Classification with Energy Trajectory and Voice Quality Measurements

“…In contrast, low tense vowels retract the tongue, so that the pharyngeal region is constricted. It is possible to express these articulatory configurations using the distinctive features [atr] (advanced tongue root) and [ctr] (constricted tongue root), respectively [5].…”