Two-dimensional parsing of the acoustic stream explains the Iambic-Trochaic Law.

Listeners parse the speech signal effortlessly into words and phrases, but many questions remain about how. One classic idea is that rhythm-related auditory principles play a role, in particular, that a psycho-acoustic "iambic-trochaic law" (ITL) ensures that alternating sounds varying in intensity are perceived as recurrent binary groups with initial prominence (trochees), while alternating sounds varying in duration are perceived as binary groups with final prominence (iambs). We test the hypothesis that the ITL is in fact an indirect consequence of the parsing of speech along two in-principle orthogonal dimensions: prominence and grouping. Results from several perception experiments show that the two dimensions, prominence and grouping, are each reliably cued by both intensity and duration, while foot type is not associated with consistent cues. The ITL emerges only when one manipulates either intensity or duration in an extreme way. Overall, the results suggest that foot perception is derivative of the cognitively more basic decisions of grouping and prominence, and the notions of trochee and iamb may not play any direct role in speech parsing. A task manipulation furthermore gives new insight into how these decisions mutually inform each other.

The Iambic-Trochaic Law (ITL) asserts that listeners associate greater acoustic intensity with group beginnings and greater duration with group endings. Some researchers have assumed a natural connection between these perceptual tendencies and universal principles underlying linguistic categories of rhythm. The experimental literature on ITL effects is limited in three ways. Few studies of listeners' perceptions of alternating sound sequences have used speech-like stimuli, cross-linguistic testing has been inadequate and existing studies have manipulated intensity and duration singly, whereas these features vary together in natural speech. This paper reports the results of three experiments conducted with native Zapotec speakers and one with native English speakers. We tested listeners' grouping biases using streams of alternating syllables in which intensity and duration were varied separately, and sequences in which they were covaried. The findings suggest that care should be taken in assuming a natural connection between the ITL and universal principles of prosodic organisation.

1 The Relevance of Psychophysics for Speech Perception.- The role of psychophysics in understanding speech perception.- Central and peripheral processes in the perception of speech and nonspeech sounds.- Psychophysics versus specialized processes in speech perception: an alternative perspective.- Speech perception and the role of long-term memory.- Levels of representation of phonemes and bandwidth of spectral-temporal integration.- General discussion of session 1.- 2 Separation of Acoustic Events.- The meaning of duplex perception: sounds as transparant objects.- Perceptual separation of speech from concurrent sounds.- Sound separation and auditory perceptual organization.- On the significance of spectral synchrony for signal detection.- Auditory enhancement in speech perception.- General discussion of session 2.- 3 Dynamic Aspects.- Trading relations, acoustic cue integration, and context effects in speech perception.- Perceptual integration of rise time and silence in affricate/fricative and pluck/bow continua.- Reversal of the rise-time cue in the affricate/fricative contrast: an experiment on the silence of sound.- Possible acoustic bases for the perception of voicing contrasts.- Is there a natural sensitivity at 20ms in relative tone-onset-time continua? A reanalysis of Hirsh's (1959) data.- Auditory constraints on speech perception.- Studies of possible psychoacoustic factors underlying speech perception.- Perception of tone, band, and formant sweeps.- Psychophysical representation of stop consonant and temporal masking in speech.- Effects of stimulus dynamics on frequency discrimination.- Extending the search for a psychophysical basis for dynamic phonetic patterns.- General discussion of session 3.- 4 Timbre (Peripheral Constraints and Central Processes in the Perception of Complex Signals)..- Psychophysics of audio signal processing and the role of pitch in speech..- Does the human auditory system include large scale spectral integration?.- Some aspects of the sound of speech sounds.- Involvement of the critical band in identification, perceived distance, and discrimination of vowels.- Profile analysis and speech perception.- General discussion of session 4.- 5 Physiological Correlates of Speech Perception.- Peripheral auditory processing of speech information: implications from a physiological study of intensity discrimination.- Organization of the cochlear nucleus for information processing.- Changes in the phonemic quality and neural representation of a vowel by alteration of the relative phase of harmonics near F1.- Phase vowels.- Nonlinear responses, in the auditory nerve to vowel-related complex stimuli.- Discussion of physiological correlates of speech perception.- General discussion of session 5.- 6 Primary Speech Percepts.- English and French speech processing: some psycholinguistic investigations.- Units of organization and analysis in the perception of speech.- Implications from infant speech studies on the unit of perception.- General discussion of session 6.- 7 Psychophysics and Speech Perception in the Hearing-Impaired.- Relationship between psychophysical abilities and speech perception for subjects with unilateral and bilateral cochlear hearing impairments.- Speech-reception threshold in a fluctuating background sound and its possible relation to temporal auditory resolution.- Differences in listening strategies between normal and hearing-impaired listeners.- Critical bands in the perception of speech signals by normal and sensorineural hearing loss listeners.- Phase and the hearing-impaired.

Hemispheric specialization for speech and non-verbal stimuli in Chinese and French Canadian subjects

Comparison of Mandarin tone and speech perception between advanced combination encoder and continuous interleaved sampling speech-processing strategies in children

ImportanceContemporary cochlear implants (CIs) are well established as a technology for people with severe‐to‐profound sensorineural hearing loss, with their effectiveness having been widely reported. However, for tonal language CI recipients, speech perception remains a challenge: Conventional signal processing strategies have been demonstrated to possibly provide insufficient information to encode tonal cues, and CI recipients have exhibited considerable deficits in tone perception. Thus, some tonal language–oriented sound‐processing strategies have been introduced. The effects of available tonal language–oriented strategies on tone perception are reviewed and evaluated in this study. The results may aid in designing and improving tonal language–appropriate sound‐processing strategies for CI recipients.ObjectiveThe objective of this systematic review was to investigate the effects of tonal‐language‐oriented signal processing strategies on tone perception, music perception, word and sentence recognition.MethodsTo evaluate the effects of tonal language–oriented strategies on tone perception, we conducted a systematic review. We searched for relevant reports dated from January 1979 to July 2017 using PubMed, Cochrane Library, EBSCO, Web of Science, EMBASE, and 4 Chinese periodical databases (CBMdisc, CNKI, VIP, and Wanfang Data).ResultsAccording to our search strategy, 672 potentially eligible studies were retrieved from the databases, with 12 of these studies included in the final review after a 4‐stage selection process. The majority of sound‐processing strategies designed for tonal language were HiResolution® with Fidelity 120 (HiRes 120), fine structure processing, temporal fine structure (TFS), and C‐tone. Generally, acute or short‐term comparisons between the tonal language–oriented strategies and the conventional strategy did not reveal statistically significant differences in speech perception (or show a small improvement). However, a tendency toward improved tone perception and subjectively reported overall preferred sound quality was observed with the tonal language–oriented strategies.InterpretationConventional signal processing strategies typically provided very limited F0 information via temporal envelopes delivered to the stimulating electrodes. In contrast, tonal language–oriented coding strategies attempted to present more spectral information and TFS cues required for tone perception. Thus, a tendency of improved performance in tonal language perception in CI users was shown.

The first objective of this study was to create a recorded Mandarin Early Speech Perception (MESP) test based on the English Early Speech Perception test (), a closed-set assessment tool for evaluation of early speech perception abilities in children. The second objective was to determine whether each of the MESP subtests is appropriate for children with these abilities. The third objective was to examine the effects of early exposure to and use of Putonghua (Standard Mandarin), as used for the recordings, on performance for each subtest. MESP test items were developed by sampling approximately 200 picturable words, twice the number required for the test, from Chinese children's books. A sample (N = 17) of 2.0- to 5.0-yr-old developmentally normal children identified the words from pictures and then recognized the words when tested with live voice by pointing to the pictures. Only words that were accurately identified and recognized by children of all ages were selected. An additional sample (N = 92) of 2.0- to 5.0-yr-old developmentally normal children was tested with the subtests of the MESP. Information about each child's daily Putonghua exposure and use was used to separate the sample into two groups. Subtest scores for the two groups were compared to examine the effects of early dialect exposure on performance. Fewer than 2% of the words used in the six subtests of the MESP were incorrectly named and recognized. Each subtest measures a different category of early speech perception. The categories are hierarchically structured. Categories 1, 2, and 3, Speech Sound Detection, Speech Pattern Perception, and Spondee Recognition, parallel the ESP. Categories 4, 5, and 6 of the MESP, Vowel Perception, Consonant Perception, and Tone Perception, are more difficult tests that provide information about segmental and tonal cues for Mandarin speech perception. All children in all age groups reached all MESP categories successfully, with the exception of three children in the youngest age group for the Tone Perception test. The two oldest groups of children who were not exposed primarily to Putonghua had slightly lower scores on both the Consonant and Tone Perception tests than children who were primarily exposed to Putonghua. These results suggest that development of tone perception continues beyond the MESP age range. Nonetheless, children as young as 2 yr of age could be tested on all of the MESP subtests. The development of the MESP has produced a recorded objective test for the evaluation of early speech perception in Mandarin-speaking children using a standardized protocol. The hierarchical structure of the first three MESP categories parallels that of the ESP, while restricting the occurrence of some tones. Additional MESP categories allow control and variation of Mandarin segmental and tonal contrasts. The MESP is part of a Mandarin hierarchical test battery for assessment of speech perception in young children.

Rhythm in music and speech can be characterized by a constellation of several acoustic cues. Individually, these cues have different effects on rhythmic perception: sequences of sounds alternating in duration are perceived as short-long pairs (weak-strong/iambic pattern), whereas sequences of sounds alternating in intensity or pitch are perceived as loud-soft, or high-low pairs (strong-weak/trochaic pattern). This perceptual bias—called the Iambic-Trochaic Law (ITL)–has been claimed to be an universal property of the auditory system applying in both the music and the language domains. Recent studies have shown that language experience can modulate the effects of the ITL on rhythmic perception of both speech and non-speech sequences in adults, and of non-speech sequences in 7.5-month-old infants. The goal of the present study was to explore whether language experience also modulates infants’ grouping of speech. To do so, we presented sequences of syllables to monolingual French- and German-learning 7.5-month-olds. Using the Headturn Preference Procedure (HPP), we examined whether they were able to perceive a rhythmic structure in sequences of syllables that alternated in duration, pitch, or intensity. Our findings show that both French- and German-learning infants perceived a rhythmic structure when it was cued by duration or pitch but not intensity. Our findings also show differences in how these infants use duration and pitch cues to group syllable sequences, suggesting that pitch cues were the easier ones to use. Moreover, performance did not differ across languages, failing to reveal early language effects on rhythmic perception. These results contribute to our understanding of the origin of rhythmic perception and perceptual mechanisms shared across music and speech, which may bootstrap language acquisition.

The use of spoken language requires sophisticated perception and processing of speech sounds and sound patterns. It is still a matter of debate to what extent speech sound perception is based on special mechanisms unique to humans or on more general auditory processing mechanisms also present in other species. This article provides an overview of comparative research on the abilities of non-human animals (mammals and birds) to perceive and process speech sounds. It shows that phenomena like categorical perception of speech sounds, biases in vowel perception, context dependency of sound categorization, speaker normalization as well as speaker identification can all be found in several animal species. Also, like humans, animals can categorize speech sounds flexibly along different orthogonal dimensions (e.g., categorize speech sounds by word or by speaker sex) and are sensitive to prosodic patterns. While the perceptual sensitivities of humans and animals, as well as among different animal species, are not necessarily identical, they seem equivalent in their degree of sophistication. Although there is a need for more extensive and systematic comparative studies, human speech perception thus seems based on broadly shared sensitivities. These are likely to have arisen because all animals that use vocalizations to communicate need to be able to identify meaningful variations in sounds and sound patterns. Such sensitivities may have guided the evolution of speech sounds, rather than being a consequence of the evolution of spoken language.

Perception of tone plays an important role in speech and music perception. Due to the low number of electrodes of the cochlear implants compared to the number of hair cells and neural endings, tonotopic perception of tone is very limited with cochlear implants compared to normal hearing. However, the perception of tone by implanted patients usually exceeds this tonotopic limit. We studied the perception of tone by implanted patients and the influence of the coding strategy in this ability.

The developmental course of lexical tone perception in the first year of life

Rhythm perception in speech and non-speech acoustic stimuli has been shown to be affected by general acoustic biases as well as by phonological properties of the native language of the listener. The present paper extends the cross-linguistic approach in this field by testing the application of the iambic-trochaic law as an assumed general acoustic bias on rhythmic grouping of non-speech stimuli by speakers of three languages: Arabic, Hebrew and German. These languages were chosen due to relevant differences in their phonological properties on the lexical level alongside similarities on the phrasal level. The results show Iambic-Trochaic-Law (ITL) conforming weak–strong grouping for duration-cued acoustic salience. However, only German participants judged intensity-varying sequences as strong–weak; no grouping preferences were found for speakers of Arabic and Hebrew. Overall these results suggest that prosodic properties of the phonological phrase and of the lexical level of the native language show differing effects on rhythmical grouping.

Twelve Ss participated in a study investigating redundant and orthogonal stimulus dimensions in partial reports (PRs) from visual immediate (iconic) memory. Each S was tested under four conditions: PRs on the bases of size, color, and letter vs. digit, and whole report (WR). Each of the three selection criterion dimensions occurred as the only varying dimension, and with each of the other two dimensions varying redundantly and orthogonally with it Results indicated PRs significantly better than WR for size and color only, supporting the contention that a simpl physical characteristic is necessary for a PR effect. Differences between reports from redundant and orthogonal stim ulus groups were significant for both irrelevant dimensions within each of the three selection criteria. The data support a perceptual structuring hypothesis, but do not provide validation for either a hierarchical series of feature tests or an integral-separable dimension dichotomy. They do indicate that irrelevant dimensions do have an effect in iconic search, and that therefore the iconic store must be fairly close to a full representation of the stimulus.

We examined the relative contribution of auditory processing abilities (tone perception and speech perception in noise) after controlling for short-term memory capacity and vocabulary, to narrative language comprehension in children with developmental language disorder. Two hundred and sixteen children with developmental language disorder, ages 6 to 9 years (Mean = 7; 6), were administered multiple measures. The dependent variable was children's score on the narrative comprehension scale of the Test of Narrative Language. Predictors were auditory processing abilities, phonological short-term memory capacity, and language (vocabulary) factors, with age, speech perception in quiet, and non-verbal IQ as covariates. Results showed that narrative comprehension was positively correlated with the majority of the predictors. Regression analysis suggested that speech perception in noise contributed uniquely to narrative comprehension in children with developmental language disorder, over and above all other predictors; however, tone perception tasks failed to explain unique variance. The relative importance of speech perception in noise over tone-perception measures for language comprehension reinforces the need for the assessment and management of listening in noise deficits and makes a compelling case for the functional implications of complex listening situations for children with developmental language disorder.

Introduction Two aspects of the F0 - the F0 level (high, middle, low) and the F0 contour (static, rising, falling) – are generally considered the perceptual correlates of lexical tones in tone languages, including Mandarin Chinese (Gandour, 1983), Cantonese (Khouw & Ciocca, 2007), and Thai (Gandour, Potisuk, & Dechongkit, 1994). Besides the dominant role of spectral information, much attention has recently been paid to the importance of temporal information in parsing the acoustic signal into relevant segments for decoding during auditory/speech processing (Luo & Poeppel, 2012). Acoustic cues from the temporal waveform envelope have also been shown to successfully cue tone perception in Mandarin Chinese (Whalen & Xu, 1992) as well as Cantonese (Zhou, 2012). Of the various cues to amplitude envelope, rise time, defined as the time taken for a sound to reach its maximum amplitude (Rosen, 1992), is proposed to be an important perceptual cue for the representation of amplitude envelope. The amplitude rise time has been found to be important in facilitating prosodic and syllable segmentation processes in children (Carpenter & Shahi, 2013; Leong, Hämäläinen, Soltesz, & Goswami, 2011), which are arguably critical for the formation of well-specified phonological representations (Goswami, 2011). Hence, one may question whether the rise time of sound amplitude envelope may likewise play a role in processing lexical tones. In other words, to process tones efficiently may entail the encoding of both spectral and temporal cues present in the speech signal to derive tone representations. The present study is the first examination of neural processes underlying the discrimination of the high rising and low rising tones T2/T5 in Hong Kong Cantonese (HKC) from two groups of typically-developed native speakers of HKC with comparable language and musical backgrounds. The participant groups represented, respectively, the pattern of good perception and good production of all Cantonese tones [+Per+Pro], and that of good perception of all tones but poor production of specifically the T2/T5 distinction [+Per-Pro]. Electrophysiological responses to the contrasts of pitch and amplitude envelope between T2 and T5 were measured to allow us to assess the timing and strength of neural activities associated with the auditory stimuli unfolding over time. Any difference in neural response between the two groups would shed light on how the acoustic cues of pitch and amplitude envelope are differentially represented in their auditory memory, and enable us to consider the relationship between perception and production. Method A total of 138 native speakers of Cantonese, all born and raised in Hong Kong, were recruited. No speaker reported a history of hearing abnormalities. According to the Edinburgh Handedness Inventory (Oldfield, 1971), they were all right-handers. They first participated in a tone perception and a tone production task. On the basis of their performance on these tasks, 41 participants were invited back to carry out a passive oddball task. The participants were classified into two groups, i.e. [+Per+Pro] (N = 20, female = 8) and [+Per-Pro] (N = 21, female = 13). The EEG experiment employed the passive oddball paradigm and was conducted in a sound-attenuated electrically shielded booth. Three syllables /fu1/, /fu2/ and /fu5/ were used. The experiment consisted of four oddball conditions of different Standard/Deviant pairs, including T2/T5 and T5/T2 as two experimental conditions, and two control conditions by pairing T2 and T5 with T1 as the common standard, i.e. T1/T2 and T1/T5. For the control conditions, the divergence point was at the vowel onset, where pitch height of the two stimuli begin to deviate. For the experimental conditions, as T2 resembled T5 in the early part of the pitch contour, the two began to diverge at 250 post stimulus onset. Additionally, in the period of 100 to 250 ms where the pitch contours of T2 and T5 fully overlapped, the amplitude rise time, computed as the duration between the vowel onset and amplitude peak during the overlapping pitch period (Tarr, 2013), differed between them. The rise time was 120 ms for T2 and 70 ms for T5. In each condition, the standard stimuli were presented in 85% of the trials, and the deviant occurred on 15% (or 80) of the trials in a quasi-random sequence. The sequence of blocks was rotated across participants. The pre-processed EEG data were analyzed in two ways. Statistical differences between the true and dummy waves were evaluated by a non-parametric cluster-based random permutation approach implemented in Fieldtrip (see Maris & Oostenveld, 2007). The conventional analysis was also performed to examine whether the two groups differed in the ERPs to rise time, the magnitude and latency of the MMN and P3a to pitch level/contour. To explore the relationship between perception and production, correlations between the T2-T5 production accuracy and the perceptual responses were computed, including the behavioral response latency to trials involving T2 and T5 in the tone discrimination task, as well as the neural correlates to rise time and pitch height/contour between T2 and T5. Results and Discussion Behavioral results Results of the tone discrimination task showed that the [+Per-Pro] group had significantly longer response time (RT) of trials involving T2 and T5 than the [+Per+Pro] group, [M[+Per+Pro] = 1046.18 ms, SD = 80.19; M[+Per-Pro] = 1204.54 ms, SD = 177.51; t(39)= -3.57, p = .001, Cohen's d = 1.14], although both groups achieved high accuracies (above 98%). ERP results The results of the cluster-level permutation test revealed several significant clusters in different conditions in the two participant groups (see Figure 1). For clusters that were considered MMNs, the [+Per+Pro] group exhibited the component in the conditions of T1/T5, T1/T2, and T2/T5 -- between 100 and 166 ms (post-divergence point unless specified otherwise) for T1/T2 (p < .001), between 100 and 166 ms for T1/T5 (p = .006), and between 150 and 200 ms for T2/T5 (p = .015). The [+Per-Pro] group showed MMNs in the T1/T2 (110 – 166 ms, p = .005), T1/T5 (104 – 154 ms, p = .024) and T2/T5 (150 – 200 ms, p = .015) conditions. No significant negative cluster was observed in the T5/T2 condition for either group. For P3a, only the T1/T2 condition elicited a significant positive cluster immediately following the MMN for both groups, in the time window of 300 to 400 ms for [+Per+Pro] (p = .025) and 342 to 404 ms for [+Per-Pro] (p = .039). For brain responses to rise time, both participant groups exhibited an early positive-going cluster in the T2/T5 condition in the time window between 62 and 154 ms for [+Per+Pro] (p = .015) and between 64 and 144 ms for [+Per-Pro] (p = .022). For the T5/T2 condition, an early negative-going component was observed only in the [+Per+Pro] group in the time window of 36 to 176 ms (p = .039). T-tests and mixed model ANOVAs of neural responses at Fz revealed that the [+Per+Pro] group showed a shorter MMN latency than the [+Per-Pro] group [t(39) = -2.305, p < .027, Cohen's d = - .74] in the T1/T2 condition. For the MMNs and P3a in the experimental conditions of T2/T5 and T5/T2, significant main effects of condition were found for the MMN mean amplitude [F(2, 39) = 5.85, p = .020, η2 = .13] and the MMN peak latency [F(2, 39) = 10.83, p = .002, η2 = .22], with stronger MMN responses to T2/T5 than to T5/T2 but longer latency to T2/T5 relatively to T5/T2. For rise time, results of a mixed ANOVA of the average amplitudes showed main effects of tone condition [F = (2, 39) = 47.18, p < .001, η2 = .55] and group [F = (2, 39) = 75.89, p = .017, η2 = .14], with T5 eliciting more positive responses than T2, and stronger responses from the [+Per+Pro] than [+Per-Pro] group. Correlations between production accuracy of the two rising tones and perceptual measures found that the averaged production accuracy was negatively correlated with the discrimination RT (r = -.502, p = .001), with shorter discrimination RTs associated with higher production accuracy. In addition, the production accuracy was positively correlated with the mean amplitude of brain responses to rise time of T5 (r = .421, p = .006), the larger the response, the higher the production accuracy. In summary, the present study demonstrated that tone perception is highly dynamic and exploits different acoustic cues at different stages of processing – rise time at the sensory/perceptual level and pitch feature at the cognitive level, as the auditory signal unfolds over time. Moreover, our findings revealed differential sensitivities between individuals with and without distinctive production of the two rising tones as evidenced by the differences in discrimination latency of the two tones and magnitude of brain response to short rise time. The individual differences found in production are proposed to have a perceptual origin, in that less defined phonological representations lead to less distinctive production.