Natural Infant-Directed Speech Facilitates Neural Tracking of Prosody

Infants prefer to be addressed with infant-directed speech (IDS). IDS benefits language acquisition through amplified low-frequency amplitude modulations. It has been reported that this amplification increases electrophysiological tracking of IDS compared to adult-directed speech (ADS). It is still unknown which particular frequency band triggers this effect. Here, we compare tracking at the rates of syllables and prosodic stress, which are both critical to word segmentation and recognition. In mother-infant dyads (n=30), mothers described novel objects to their 9-month-olds while infants' EEG was recorded. For IDS, mothers were instructed to speak to their children as they typically do, while for ADS, mothers described the objects as if speaking with an adult. Phonetic analyses confirmed that pitch features were more prototypically infant-directed in the IDS-condition compared to the ADS-condition. Neural tracking of speech was assessed by speech-brain coherence, which measures the synchronization between speech envelope and EEG. Results revealed significant speech-brain coherence at both syllabic and prosodic stress rates, indicating that infants track speech in IDS and ADS at both rates. We found significantly higher speech-brain coherence for IDS compared to ADS in the prosodic stress rate but not the syllabic rate. This indicates that the IDS benefit arises primarily from enhanced prosodic stress. Thus, neural tracking is sensitive to parents’ speech adaptations during natural interactions, possibly facilitating higher-level inferential processes such as word segmentation from continuous speech.

What Does Your Voice Reveal About You?

The first goal of the present study was to explore how 21 voice measures related to self-reported personality and communication styles. The second goal was to test the assertion of Trait Activation Theory (TAT) that traits are activated in relevant situations and that verbal behavior is the result of an interplay between individual differences and situations. The voice of 138 participants was measured in the lab via steady voice and continuous speech tasks, whereas personality and communication styles were self-reported using the HEXACO and Communication Styles Inventory. To test TAT, four scenarios were developed to activate the communication styles of Informality and Expressiveness. It was hypothesized that the activated communication styles will interact with relevant situations and will be expressed through changes in voice (i.e., pitch variation). Regarding the first goal, an explorative approach revealed that voice characteristics are informative mainly for the personality traits of Openness to Experience, Emotionality, and Conscientiousness and the communication styles of Emotionality and Questioningness. Regarding the second goal, the interactions between situations and communication styles provided mixed support for TAT. Implications and limitations of the study are discussed.

Применение алгоритма аппроксимации графика долей энергии для определения пауз в речевом сигнале

В данной работе рассматривается речевой сигнал как набор фрагментов, содержащих речевые компоненты и фрагменты с шумами, соответствующие паузам между словами. Ставится задача по составлению решающей функции, способной принять или отвергнуть гипотезу об отсутствии речи в отрезке речевого сигнала. На основе субполосного метода для отрезка речевого сигнала составляется его распределение энергий по частотам. Для этого распределения в дальнейшем применяется процедура аппроксимации смесью радиально-базисными функциями (функциями Гаусса). Смесь представляет собой взвешенную сумму радиально-базисных функций и равномерно-распределённой составляющей. По соотношению максимальных значений компонент смеси составляется решающее правило. Для проведения вычислительного эксперимента вводится нелинейность «зона нечувствительности», выбор которой обусловлен особенностями электрической активности путей и центров слуховой системы. В работе приводится результат применения алгоритма определения пауз в речевом сигнале. В качестве рабочего материала использовалась база размеченных речевых фрагментов американского агентства передовых оборонных исследовательских проектов DARPA TIMIT Acoustic-Phonetic Continuous Speech Corpus. Всего было обработано 100 звукозаписей, размер отрезка анализа был взят 9 миллисекунд, частота дискретизации 16000Гц. Для проверки работоспособности предлагаемого алгоритма были оценены ошибки первого рода «пропуск цели» — когда алгоритм не начал отмечать паузу, но такая отметка присутствует при ручной расстановке, а также ошибки второго рода «ложная тревога» — когда произошла ошибочная постановка паузы. Полученные в ходе вычислительных экспериментов результаты позволяются судить о достаточно высокой эффективности предлагаемого подхода для определения пауз в речевом сигнале.

From speech to language

This study proposes a novel exploration of perceived prosodic highlights in continuous speech, focusing on the alternative function of indexing and projecting information content deployment in the speech context. Given the assumption that prosodic highlight allocation directly reflects the interlocutors’ information content deployment, this study foregrounds perception-based prominences for indexing both the key information (KEY) and the projector (PJR) that projects the deployment of key/focal information. Two information content planning units (PJR plus its respective projection PJN, and KEY) prompted by prosodic highlights were established, based on quantitative analyses and discriminative acoustic features. Additional analyses confirm a general heavy-to-light information distribution across both units, showcasing that the relative projection trajectory size in the PJR-PJN unit is positively correlated to its position within discourse-prosodic units. Current results, therefore, directly substantiate the cognitive explanation of prosodic projection in speech, as evidence beyond syntactic relationships are drawn and prosodic projection is shown to involve perceived prosodic highlight allocation and information deployment in a fixed pattern. Explorations of prosody-prompted projection shed light on a more comprehensive account of the mechanism behind information planning, hence facilitating a deeper understanding of the composition of context prosody and the derivation of linguistic invariants from speech.