Parents’ hyper-pitch and vowel category compactness in infant-directed speech are associated with 18-month-old toddlers’ expressive vocabulary

The present study examines the acoustic properties of infant-directed speech (IDS) as compared to adult-directed speech (ADS) in Norwegian parents of 18-month-old toddlers, and whether these properties relate to toddlers’ expressive vocabulary size. Twenty-one parent- toddler dyads from Tromsø, Northern Norway participated in the study. Parents (16 mothers, 5 fathers), speaking a Northern Norwegian dialect, were recorded in the lab reading a storybook to their toddler (IDS register), and to an experimenter (ADS register). The storybook was designed for the purpose of the study, ensuring identical linguistic contexts across speakers and registers, and multiple representations of each of the nine Norwegian long vowels. We examined both traditionally reported measures of IDS: pitch, pitch range, vowel duration and vowel space expansion, but also novel measures: vowel category compactness and vowel category distinctiveness. Our results showed that Norwegian IDS, as compared to ADS, had similar characteristics as in other languages: higher pitch, wider pitch range, longer vowel duration, and expanded vowel space area; in addition, it had less compact vowel categories. Further, parents’ hyper-pitch, that is, the within-parent increase in pitch in IDS as compared to ADS, and vowel category compactness in IDS itself, were positively related to toddlers' vocabulary. Our results point towards potentially facilitating roles of parents’ increase in pitch when talking to their toddler and of consistency in vowel production in early word learning.

Back Vowel Dynamics and Distinctions in Southern American English

Southern American English is spoken in a large geographic region in the United States. Its characteristics include back-vowel fronting (e.g., in goose, foot, and goat), which has been ongoing since the mid-nineteenth century; meanwhile, the low back vowels (in lot and thought) have recently merged in some areas. We investigate these five vowels in the Digital Archive of Southern Speech, a legacy corpus of linguistic interviews with sixty-four speakers born 1886-1956. We extracted 89,367 vowel tokens and used generalized additive mixed-effects models to test for socially-driven changes to both their relative phonetic placements and the shapes of their formant trajectories. Our results reinforce previous descriptions of Southern vowels while contributing additional phonetic detail about their trajectories. Goose-fronting is a change in progress, with greatest fronting after coronal consonants. Goat is quite dynamic; it lowers and fronts in apparent time. Generally, women have more fronted realizations than men. Foot is largely monophthongal, and stable across time. Lot and thought are distinct and unmerged, occupying different regions of the vowel space. While their relative positions change across generations, all five vowels show a remarkable consistency in formant trajectory shapes across time. This study’s results reveal social and phonetic details about the back vowels of Southerners born in the late nineteenth and early twentieth centuries: goose-fronting was well underway, goat-fronting was beginning, but foot remained backed, and the low back vowels were unmerged.

Impact of Vocal Effort on Respiratory and Articulatory Kinematics

Purpose: The goal of this study was to examine the effects of increases in vocal effort, without changing speech intensity, on respiratory and articulatory kinematics in young adults with typical voices. Method: A total of 10 participants completed a reading task under three speaking conditions: baseline, mild vocal effort, and maximum vocal effort. Respiratory inductance plethysmography bands around the chest and abdomen were used to estimate lung volumes during speech, and sensor coils for electromagnetic articulography were used to transduce articulatory movements, resulting in the following outcome measures: lung volume at speech initiation (LVSI) and at speech termination (LVST), articulatory kinematic vowel space (AKVS) of two points on the tongue dorsum (body and blade), and lip aperture. Results: With increases in vocal effort, and no statistical changes in speech intensity, speakers showed: (a) no statistically significant differences in LVST, (b) statistically significant increases in LVSI, (c) no statistically significant differences in AKVS measures, and (d) statistically significant reductions in lip aperture. Conclusions: Speakers with typical voices exhibited larger lung volumes at speech initiation during increases in vocal effort, paired with reduced lip displacements. To our knowledge, this is the first study to demonstrate evidence that articulatory kinematics are impacted by modulations in vocal effort. However, the mechanisms underlying vocal effort may differ between speakers with and without voice disorders. Thus, future work should examine the relationship between articulatory kinematics, respiratory kinematics, and laryngeal-level changes during vocal effort in speakers with and without voice disorders. Supplemental Material https://doi.org/10.23641/asha.17065457

Chimpanzee vowel-like sounds and voice quality suggest formant space expansion through the hominoid lineage

The origins of human speech are obscure; it is still unclear what aspects are unique to our species or shared with our evolutionary cousins, in part due to a lack of a common framework for comparison. We asked what chimpanzee and human vocal production acoustics have in common. We examined visible supra-laryngeal articulators of four major chimpanzee vocalizations (hoos, grunts, barks, screams) and their associated acoustic structures, using techniques from human phonetic and animal communication analysis. Data were collected from wild adult chimpanzees, Taï National Park, Ivory Coast. Both discriminant and principal component classification procedures revealed classification of call types. Discriminating acoustic features include voice quality and formant structure, mirroring phonetic features in human speech. Chimpanzee lip and jaw articulation variables also offered similar discrimination of call types. Formant maps distinguished call types with different vowel-like sounds. Comparing our results with published primate data, humans show less F1–F2 correlation and further expansion of the vowel space, particularly for [i] sounds. Unlike recent studies suggesting monkeys achieve human vowel space, we conclude from our results that supra-laryngeal articulatory capacities show moderate evolutionary change, with vowel space expansion continuing through hominoid evolution. Studies on more primate species will be required to substantiate this. This article is part of the theme issue ‘Voice modulation: from origin and mechanism to social impact (Part II)’.

An instrumental analysis of oral monophthongs in Aceh Barat dialect of Acehnese

As among the ten most spoken languages, Acehnese inevitably has many varieties. Many previous studies on Acehnese have been heavily conducted on the northern varieties of Acehnese, leaving other Acehnese varieties unexplored. Pase dialect of Acehnese has been described to have oral and nasal monophthongs and diphthongs, but no studies on Aceh Barat dialect phonetic features of Acehnese have been made. Aceh Barat dialect has also been stigmatized as being rough and vulgar in the previous study. Thus, the current study aims to explore the instrumental analysis of Acehnese oral monophthongs by Aceh Barat speakers. Three male speakers (aged 35-50 years old) speaking only Acehnese as the local language participated in the current study. The ten Acehnese words used to target the ten phonemes were adapted from study. A total of 90 tokens of Acehnese oral vowels production were analyzed using PRAAT version 6.1.29. The oral monophthongs of the Aceh Barat dialect are generally similar to the previous study on the Pase dialect. Exception emerges for the vowel /?/ and /?/, which seems to be produced differently across the speakers. Both vowels appear to stretch further down the vowel space closer to the back vowels /u/ and / ?/, respectively.

The Pronunciation of English Low Vowels by Iraqi EFL Learners: An Intralingual Analysis

Iraqi EFL learners of English are reported to show accented pronunciation on the segmental level, which might affect their speech intelligibility. This study aimed to identify problems encountered by Iraqi EFL learners in the production of English low vowels and account for them from an intralingual perspective. The study also aimed to identify the effect of Iraqis' English language proficiency level on their pronunciation of English low vowels. Thus, learners were divided into beginners and advanced groups to determine differences between them based on their proficiency level in English. A production test was conducted to identify error patterns of twenty Iraqi EFL learners in producing low vowels. Learners’ recordings were acoustically analysed to validate the difficulties identified via the production test. Independent-samples t-tests were conducted to identify any significant differences in performance for the two groups. The results showed that learners encountered problems in the production of low vowels, especially /ɒ/, /æ/ and /ʌ/. The study concluded that these problems are probably ascribed to the complexities of the L2 vowel space, where vowels are close to each other and thus difficult to produce. Significant differences were identified between the two groups in terms of error means. Nonetheless, the comparison between the vowel chart obtained in this study and the charts offered in previous studies revealed that Iraqi EFL learners are still far from attaining approximant pronunciation. This requires reconsidering current texts, methodologies, and techniques used in teaching English pronunciation to allocate more attention to spectral differences among vowels. Keywords Low vowels production; Iraqi EFL learners; intralingual analysis; error patterns; acoustic analysis

Altered speech patterns in subjects with post-traumatic headache due to mild traumatic brain injury

Background/objective Changes in speech can be detected objectively before and during migraine attacks. The goal of this study was to interrogate whether speech changes can be detected in subjects with post-traumatic headache (PTH) attributed to mild traumatic brain injury (mTBI) and whether there are within-subject changes in speech during headaches compared to the headache-free state. Methods Using a series of speech elicitation tasks uploaded via a mobile application, PTH subjects and healthy controls (HC) provided speech samples once every 3 days, over a period of 12 weeks. The following speech parameters were assessed: vowel space area, vowel articulation precision, consonant articulation precision, average pitch, pitch variance, speaking rate and pause rate. Speech samples of subjects with PTH were compared to HC. To assess speech changes associated with PTH, speech samples of subjects during headache were compared to speech samples when subjects were headache-free. All analyses were conducted using a mixed-effect model design. Results Longitudinal speech samples were collected from nineteen subjects with PTH (mean age = 42.5, SD = 13.7) who were an average of 14 days (SD = 32.2) from their mTBI at the time of enrollment and thirty-one HC (mean age = 38.7, SD = 12.5). Regardless of headache presence or absence, PTH subjects had longer pause rates and reductions in vowel and consonant articulation precision relative to HC. On days when speech was collected during a headache, there were longer pause rates, slower sentence speaking rates and less precise consonant articulation compared to the speech production of HC. During headache, PTH subjects had slower speaking rates yet more precise vowel articulation compared to when they were headache-free. Conclusions Compared to HC, subjects with acute PTH demonstrate altered speech as measured by objective features of speech production. For individuals with PTH, speech production may have been more effortful resulting in slower speaking rates and more precise vowel articulation during headache vs. when they were headache-free, suggesting that speech alterations were related to PTH and not solely due to the underlying mTBI.