Cortical tracking of voice pitch in the presence of multiple speakers depends on selective attention

Voice pitch carries linguistic as well as non-linguistic information. Previous studies have described cortical tracking of voice pitch in clean speech, with responses reflecting both pitch strength and pitch value. However, pitch is also a powerful cue for auditory stream segregation, especially when competing streams have pitch differing in fundamental frequency, as is the case when multiple speakers talk simultaneously. We therefore investigated how cortical speech pitch tracking is affected in the presence of a second, task-irrelevant speaker. We analyzed human magnetoencephalography (MEG) responses to continuous narrative speech, presented either as a single talker in a quiet background, or as a two-talker mixture of a male and a female speaker. In clean speech, voice pitch was associated with a right-dominant response, peaking at a latency of around 100 ms, consistent with previous EEG and ECoG results. The response tracked both the presence of pitch as well as the relative value of the speaker’s fundamental frequency. In the two-talker mixture, pitch of the attended speaker was tracked bilaterally, regardless of whether or not there was simultaneously present pitch in the speech of the irrelevant speaker. Pitch tracking for the irrelevant speaker was reduced: only the right hemisphere still significantly tracked pitch of the unattended speaker, and only during intervals in which no pitch was present in the attended talker’s speech. Taken together, these results suggest that pitch-based segregation of multiple speakers, at least as measured by macroscopic cortical tracking, is not entirely automatic but strongly dependent on selective attention.

Comparative Study of Different Algorithms for a Flight Control System Design and the Potentiality of Their Integration with a Sidestick

The modern trend of developing highly automated aircraft is characterized by a transition from traditional methods and technical solutions to innovative approaches in order to control the system, inceptor and display design. This paper deals with the development and comparison of flight control system algorithms based on inverse dynamics, H-infinity and traditional feedback methods. The integration of a controller based on inverse dynamics with a novel type of sidestick, shaping the pilot output signal such that it is proportional to the control force (force sensing control—FSC), is studied. The inverse dynamics-based controller is chosen, as it provides a variance of error that is up to 2.3 times less than that of the feedback gains and up to 1.5 times less than that of the H-infinity controller in a pitch tracking task. The synergetic effect arising from the proposed integration is also evaluated. The evaluation of the effectiveness of the methods is carried out through mathematical modeling of the pilot–aircraft system and ground-based simulations on a helicopter mathematical model in a pitch tracking task.

Language experience during the sensitive period narrows infants’ sensory speech encoding----music intervention reverse it

The sensitive period for phonetic learning (6~12 months), evidenced by increases in native and declines in nonnative speech processing, represents an early milestone in language acquisition. We examined the extent that sensory encoding of speech is altered by experience during this period by testing two hypotheses: 1) early sensory encoding of nonnative speech declines as infants gain native-language experience, and 2) music intervention reverses this decline. We longitudinally measured the frequency-following response (FFR), a robust indicator of early sensory encoding along the auditory pathway, to a Mandarin lexical tone in 7- and 11-months-old monolingual English-learning infants. Infants received music intervention (music-intervention group) or no intervention (language-experience group) randomly between FFR recordings. The language-experience group exhibited the expected decline in FFR pitch-tracking accuracy to the Mandarin tone while the music-intervention group did not. Our results support both hypotheses and demonstrate that both language and music experience alter infants’ speech encoding.

method for lexical tone classification in audio-visual speech

This work presents a method for lexical tone classification in audio-visual speech. The method is applied to a speech data set consisting of syllables and words produced by a female native speaker of Cantonese. The data were recorded in an audio-visual speech production experiment. The visual component of speech was measured by tracking the positions of active markers placed on the speaker's face, whereas the acoustic component was measured with an ordinary microphone. A pitch tracking algorithm is used to estimate F0 from the acoustic signal. A procedure for head motion compensation is applied to the tracked marker positions in order to separate the head and face motion components. The data are then organized into four signal groups: F0, Face, Head, Face+Head. The signals in each of these groups are parameterized by means of a polynomial approximation and then used to train an LDA (Linear Discriminant Analysis) classifier that maps the input signals into one of the output classes (the lexical tones of the language). One classifier is trained for each signal group. The ability of each signal group to predict the correct lexical tones was assessed by the accuracy of the corresponding LDA classifier. The accuracy of the classifiers was obtained by means of a k-fold cross validation method. The classifiers for all signal groups performed above chance, with F0 achieving the highest accuracy, followed by Face+Head, Face, and Head, respectively. The differences in performance between all signal groups were statistically significant.

Prosody of Ojibwe Discourse Markers

Discourse markers (DMs) are optional, sequentially dependent sentence-initial items (Schiffrin, 1987) that are used to bracket units of talk (e.g. oh, well, because, y’know, now ). This research aims to better understand Ojibwe DMs which typically occur as the first or second element of a sentence (Fairbanks, 2016). The proposed analysis seeks to understand the prosody of Ojibwe DMs broadly and specifically their use in narrative structure. The data is drawn from Gakina Dibaajimowin Gwayakwaawan ( All Teachings are Correct ) by Nancy Jones, 2013. The analysis was done by using the programs Audacity and PRAAT to identify individual sentences and their pitch prominences. Through careful listening and pitch tracking, prosodic properties of DMs were found to indicate the following: DMs attract the most prominent pitch in the sentence. DMs are used by the speaker to attract the hearer’s attention; in this sense they are interactional (Franks-Job, 2006). DMs are used by the speaker to structure the narration; as such they interact with topic changes and emphasis (Lenk, 1998) This study creates a more complex picture of Ojibwe DMs and adds to our understanding of the language. References: Fairbanks, B. 2016. Ojibwe Discourse Markers. University of Nebraska Press. Franks-Job, B. 2006. A dynamic-interactional approach to discourse markers. In Approaches to discourse particles, K. Fischer (ed.) pp. 395–413. Amsterdam: Elsevier. Lenk, U. 1998. Discourse markers and global coherence in conversation. Journal of Pragmatics 30(2):246-257 Ogimaawigwaebiik [Nancy Jones] 2013. Gakina Dibaajimowin Gwayakwaawan. In Dibaajimowinaan; Anishinaabe Stories of Culture and respect ; Nigaanigiizhig [Jim Saint-Arnold] (ed.), Great Lakes Indian Fish & Wildlife Commission, 9-10. Raso, Tommaso. 1996. Prosodic constraints for discourse markers. Spoken Corpora and Linguistic Studies. In Spoken Corpora and Linguistics Studies , T. Raso & H. Mello (eds.) 411-467. Benjamins: Amsterdam. Schiffrin, D. 1987. Discourse Markers. doi: 10.1017/cbo9780511611841.