Pairs Of Sounds Research Articles

Teaching the Five Ws About Rules of English Pronunciation: A Tutorial View for English Learners (Episode I)

From a very long dissertation, series of simplified papers are extracted to tackle simply the English rules of pronunciation. Given the complex and labyrinthine nature of phonetics to a myriad of English learners, this simplification is ushered to be the avant-garde publication for all non-native English speakers. It pops out an abundant package of technical terms to keep it simple and straight. The theoretical part provides the reader shortly with very few fundamental concepts before delving into the practical section. Conventionally, previous papers viewed their explanation using the classical “sound pair”, contrasting voiced to unvoiced modes. To simplify, the rules of pronunciation are fully explained letter by letter using a narrative style where all involved sounds are enrolled under each letter. The conclusion is postponed to the finale for tutorial purposes.

Dissociating Contributions of the Motor Cortex to Speech Perception and Response Bias by Using Transcranial Magnetic Stimulation.

Recent studies using repetitive transcranial magnetic stimulation (TMS) have demonstrated that disruptions of the articulatory motor cortex impair performance in demanding speech perception tasks. These findings have been interpreted as support for the idea that the motor cortex is critically involved in speech perception. However, the validity of this interpretation has been called into question, because it is unknown whether the TMS-induced disruptions in the motor cortex affect speech perception or rather response bias. In the present TMS study, we addressed this question by using signal detection theory to calculate sensitivity (i.e., d′) and response bias (i.e., criterion c). We used repetitive TMS to temporarily disrupt the lip or hand representation in the left motor cortex. Participants discriminated pairs of sounds from a “ba”–“da” continuum before TMS, immediately after TMS (i.e., during the period of motor disruption), and after a 30-min break. We found that the sensitivity for between-category pairs was reduced during the disruption of the lip representation. In contrast, disruption of the hand representation temporarily reduced response bias. This double dissociation indicates that the hand motor cortex contributes to response bias during demanding discrimination tasks, whereas the articulatory motor cortex contributes to perception of speech sounds.

IDENTIFICATION OF ENVIRONMENTAL SOUNDS AND MELODIES IN SYNDROMES OF ANTERIOR TEMPORAL LOBE DEGENERATION

article i nfo Recognition of nonverbal sounds in semantic dementia and other syndromes of anterior temporal lobe degener- ation may determine clinical symptoms and help to define phenotypic profiles. However, nonverbal auditory semantic function has not been widely studied in these syndromes. Here we investigated semantic processing in two key nonverbal auditory domains - environmental sounds and melodies - in patients with semantic dementia (SD group; n = 9) and in patients with anterior temporal lobe atrophy presenting with behavioural decline (TL group; n = 7, including four cases with MAPT mutations) in relation to healthy older controls (n = 20). We assessed auditory semantic performance in each domain using novel, uniform within-modality neuropsychological procedures that determined sound identification based on semantic classification of sound pairs. Both the SD and TL groups showed comparable overall impairments of environmental sound and melody identification; individual patients generally showed superior identification of environmental sounds than melodies, however relative sparing of melody over environmental sound identification also occurred in both groups. Our findings suggest that nonverbal auditory semantic impairment is a common feature of neurodegen- erative syndromes with anterior temporal lobe atrophy. However, the profile of auditory domain involvement varies substantially between individuals. © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license

Changing Zaire to Congo: The fate of no-longer relevant mnemonic information

In an ever-changing world there is constant pressure on revising long-term memory, such when people or countries change name. What happens to the old, pre-existing information? One possibility is that old associations gradually are weakened and eventually lost. Alternatively, old and no longer relevant information may still be an integral part of memory traces. To test the hypothesis that old mnemonic information still becomes activated when people correctly retrieve new, currently relevant information, brain activity was measured with fMRI while participants performed a cued-retrieval task. Paired associates (symbol–sound and symbol–face pairs) were first learned during two days. Half of the associations were then updated during the next two days, followed by fMRI scanning on day 5 and also 18months later. As expected, retrieval reactivated sensory cortex related to the most recently learned association (visual cortex for symbol–face pairs, auditory cortex for symbol–sound pairs). Critically, retrieval also reactivated sensory cortex related to the no-longer relevant associate. Eighteen months later, only non-updated symbol–face associations were intact. Intriguingly, a subset of the updated associations was now treated as though the original association had taken over, in that memory performance was significantly worse than chance and that activity in sensory cortex for the original but not the updated associate correlated (negatively) with performance. Moreover, the degree of “residual” reactivation during day 5 inversely predicted memory performance 18months later. Thus, updating of long-term memory involves adding new information to already existing networks, in which old information can stay resilient for a long time.

Biased generalization of newly learned phonological alternations by 12-month-old infants

Previous work has suggested that learners are sensitive to phonetic similarity when learning phonological patterns (e.g., Steriade, 2001/2008; White, 2014). We tested 12-month-old infants to see if their willingness to generalize newly learned phonological alternations depended on the phonetic similarity of the sounds involved. Infants were exposed to words in an artificial language whose distributions provided evidence for a phonological alternation between two relatively dissimilar sounds ([p∼v] or [t∼z]). Sounds at one place of articulation (labials or coronals) alternated whereas sounds at the other place of articulation were contrastive. At test, infants generalized the alternation learned during exposure to pairs of sounds that were more similar ([b∼v] or [d∼z]). Infants in a control group instead learned an alternation between similar sounds ([b∼v] or [d∼z]). When tested on dissimilar pairs of sounds ([p∼v] or [t∼z]), the control group did not generalize their learning to the novel sounds. The results are consistent with a learning bias favoring alternations between similar sounds over alternations between dissimilar sounds.

Auditory localization and precedence effect: an exploratory study in infants and toddlers with visual impairment and normal vision.

The precedence effect is a spatial hearing phenomenon implicated in sound localization on reverberant environments. It occurs when a pair of sounds, with a brief delay between them, is presented from different directions; listeners give greater perceptual weight to localization cues coming from the first-arriving sound, called lead, and suppress localization cues from the later-arriving reflection, called lag. Developmental studies with sighted infants show that the first responses to precedence effect stimuli are observed at 4-5 months of life. In this exploratory study, we use the minimum audible angle (MAA) paradigm in conjunction with the observer-based psychophysical procedure to test the ability of infants and toddlers, with visual impairment and normal vision, to discriminate changes in the azimuthal position of sounds configured under precedence effect conditions. The results indicated that similar and, in some conditions, higher performances were obtained by blind toddlers when compared to sighted children of similar age, and revealed that the observer-based psychophysical procedure is a valuable method to measure auditory localization acuity in infants and toddlers with visual impairment. The video records showed auditory orienting behaviors specific of the blind children group.

Pitch and Timbre Interfere When Both Are Parametrically Varied

Pitch and timbre perception are both based on the frequency content of sound, but previous perceptual experiments have disagreed about whether these two dimensions are processed independently from each other. We tested the interaction of pitch and timbre variations using sequential comparisons of sound pairs. Listeners judged whether two sequential sounds were identical along the dimension of either pitch or timbre, while the perceptual distances along both dimensions were parametrically manipulated. Pitch and timbre variations perceptually interfered with each other and the degree of interference was modulated by the magnitude of changes along the un-attended dimension. These results show that pitch and timbre are not orthogonal to each other when both are assessed with parametrically controlled variations.

Modelling reading development through phonological decoding and self-teaching: implications for dyslexia

The most influential theory of learning to read is based on the idea that children rely on phonological decoding skills to learn novel words. According to the self-teaching hypothesis, each successful decoding encounter with an unfamiliar word provides an opportunity to acquire word-specific orthographic information that is the foundation of skilled word recognition. Therefore, phonological decoding acts as a self-teaching mechanism or ‘built-in teacher’. However, all previous connectionist models have learned the task of reading aloud through exposure to a very large corpus of spelling–sound pairs, where an ‘external’ teacher supplies the pronunciation of all words that should be learnt. Such a supervised training regimen is highly implausible. Here, we implement and test the developmentally plausible phonological decoding self-teaching hypothesis in the context of the connectionist dual process model. In a series of simulations, we provide a proof of concept that this mechanism works. The model was able to acquire word-specific orthographic representations for more than 25 000 words even though it started with only a small number of grapheme–phoneme correspondences. We then show how visual and phoneme deficits that are present at the outset of reading development can cause dyslexia in the course of reading development.

Spatially extended forward suppression in primate auditory cortex

When auditory neurons are stimulated with a pair of sounds, the preceding sound can inhibit the neural responses to the succeeding sound. This phenomenon, referred to as 'forward suppression', has been linked to perceptual forward masking. Previous studies investigating forward suppression typically measured the interaction between masker and probe sounds using a fixed sound location. However, in natural environments, interacting sounds often come from different spatial locations. The present study investigated two questions regarding forward suppression in the primary auditory cortex and adjacent caudal field of awake marmoset monkeys. First, what is the relationship between the location of a masker and its effectiveness in inhibiting neural response to a probe? Second, does varying the location of a masker change the spectral profile of forward suppression? We found that a masker can inhibit a neuron's response to a probe located at a preferred location even when the masker is located at a non-preferred location of a neuron. This is especially so for neurons in the caudal field. Furthermore, we found that the strongest forward suppression is observed when a masker's frequency is close to the best frequency of a neuron, regardless of the location of the masker. These results reveal, for the first time, the stability of forward masking in cortical processing of multiple sounds presented from different locations. They suggest that forward suppression in the auditory cortex is spectrally specific and spatially broad with respect to the frequency and location of the masker, respectively.

Action perception via auditory information: Agent identification and discrimination with complex movement sounds

Action and perception are represented in a common framework. Greater motor experience should therefore lead to improved perception. This has been shown with the help of visual stimuli. Given that rhythm and timing are important factors in movement perception, auditory self-recognition should also be superior to recognition of auditory stimuli produced by others. To test this hypothesis, we examined performance in a discrimination and an identification task with movement sounds produced by participants themselves (motor and auditory experiences), by the partner of the participant within the experimental study (auditory experience), and by strangers (no experience). The results of the discrimination task show that participants could distinguish between identical and different sound pairs independent of the agent. The results of the identification task show that participants could identify their own movement sounds significantly better than strangers' sounds. The coupling of action and perception thus seems detectable via naturally emerging movement sounds (auditory information). Taken together the present study confirms and extends current theories regarding action-perception coupling, by providing evidence that self–other effects occur in the auditory domain using movement sounds. Future research should explore the underlying (neurophysiological) mechanisms that account for the present results.

Behavioural changes in dairy cows with lameness in an automatic milking system

There is a tendency worldwide for the automation of farms; this has included the introduction of automatic milking systems (AMS) in the dairy industry. Lameness in dairy cows is highly prevalent and painful. These impacts potentially affect not only animal welfare, but also farm economies. Three independent observational studies were carried out to assess the impact of lameness on the behaviour of zero grazed high yielding Holstein cows managed in an AMS. The aim of the first study was to examine the impact of lameness on rumination time, the second study investigated differences between lame and sound dairy cows in total eating time and the third study assessed the impact of lameness on milking behaviour (frequency and time of visits to the AMS). In the first study data from 150 cows were used to analyse rumination (collected using rumination collars) for the 48h following locomotion scoring. A multilevel linear regression demonstrated that lameness had a small but significant negative association (coefficient: −7.88 (SE: 3.93)) with rumination. In the second study the behaviour of eleven matched lame and sound pairs of cows at the feed face was analysed for 24h after locomotion scoring. Each feeding behaviour variable (total duration time, frequency of feeding bouts and length of bouts) was analysed using individual single level regression models. There was a significant negative association between total feeding time and lameness (coefficient: −73.65 (SE: 25.47)) and the frequency of feeding bouts and lameness (−9.93 (2.49)). Finally, the third observational study used 38 matched pairs of lame and sound cows. Data on the number and timings of visits to the AMS were collected for 24h after each locomotion score and analysed using a binomial logistic regression model. There was a significant difference in AMS visits between groups; lame animals visiting the robot less frequently than sound cows (median difference 0.50 milking visits; T=256.0; N=25; p=0.01) and lame cows were 0.33 times less likely to visit the AMS between 24:01 and 06:00. Results from these studies reveal that lameness in an AMS affected feeding behaviour, rumination and AMS visits. All of these impacts are likely to have negative consequences for farm profitability, but also implications for the health and welfare of the animals.

Speech training alters tone frequency tuning in rat primary auditory cortex

Previous studies in both humans and animals have documented improved performance following discrimination training. This enhanced performance is often associated with cortical response changes. In this study, we tested the hypothesis that long-term speech training on multiple tasks can improve primary auditory cortex (A1) responses compared to rats trained on a single speech discrimination task or experimentally naïve rats. Specifically, we compared the percent of A1 responding to trained sounds, the responses to both trained and untrained sounds, receptive field properties of A1 neurons, and the neural discrimination of pairs of speech sounds in speech trained and naïve rats. Speech training led to accurate discrimination of consonant and vowel sounds, but did not enhance A1 response strength or the neural discrimination of these sounds. Speech training altered tone responses in rats trained on six speech discrimination tasks but not in rats trained on a single speech discrimination task. Extensive speech training resulted in broader frequency tuning, shorter onset latencies, a decreased driven response to tones, and caused a shift in the frequency map to favor tones in the range where speech sounds are the loudest. Both the number of trained tasks and the number of days of training strongly predict the percent of A1 responding to a low frequency tone. Rats trained on a single speech discrimination task performed less accurately than rats trained on multiple tasks and did not exhibit A1 response changes. Our results indicate that extensive speech training can reorganize the A1 frequency map, which may have downstream consequences on speech sound processing.

Evidence for distinct human auditory cortex regions for sound location versus identity processing

Neurophysiological animal models suggest that anterior auditory cortex (AC) areas process sound-identity information, whereas posterior ACs specialize in sound location processing. In humans, inconsistent neuroimaging results and insufficient causal evidence have challenged the existence of such parallel AC organization. Here we transiently inhibit bilateral anterior or posterior AC areas using MRI-guided paired-pulse transcranial magnetic stimulation (TMS) while subjects listen to Reference/Probe sound pairs and perform either sound location or identity discrimination tasks. The targeting of TMS pulses, delivered 55–145 ms after Probes, is confirmed with individual-level cortical electric-field estimates. Our data show that TMS to posterior AC regions delays reaction times (RT) significantly more during sound location than identity discrimination, whereas TMS to anterior AC regions delays RTs significantly more during sound identity than location discrimination. This double dissociation provides direct causal support for parallel processing of sound identity features in anterior AC and sound location in posterior AC.

The time course of episodic associative retrieval: Electrophysiological correlates of cued recall of unimodal and crossmodal pair-associate learning

Little is known about the time course of processes supporting episodic cued recall. To examine these processes, we recorded event-related scalp electrical potentials during episodic cued recall following pair-associate learning of unimodal object-picture pairs and crossmodal object-picture and sound pairs. Successful cued recall of unimodal associates was characterized by markedly early scalp potential differences over frontal areas, while cued recall of both unimodal and crossmodal associates were reflected by subsequent differences recorded over frontal and parietal areas. Notably, unimodal cued recall success divergences over frontal areas were apparent in a time window generally assumed to reflect the operation of familiarity but not recollection processes, raising the possibility that retrieval success effects in that temporal window may reflect additional mnemonic processes beyond familiarity. Furthermore, parietal scalp potential recall success differences, which did not distinguish between crossmodal and unimodal tasks, seemingly support attentional or buffer accounts of posterior parietal mnemonic function but appear to constrain signal accumulation, expectation, or representational accounts.

Perception of Musical Timbre by Cochlear Implant Listeners

Several studies have shown that the ability to identify the timbre of musical instruments is reduced in cochlear implant (CI) users compared with normal-hearing (NH) listeners. However, most of these studies have focused on tasks that require specific musical knowledge. In contrast, the present study investigates the perception of timbre by CI subjects using a multidimensional scaling (MDS) paradigm. The main objective was to investigate whether CI subjects use the same cues as NH listeners do to differentiate the timbre of musical instruments. Three groups of 10 NH subjects and one group of 10 CI subjects were asked to make dissimilarity judgments between pairs of instrumental sounds. The stimuli were 16 synthetic instrument tones spanning a wide range of instrument families. All sounds had the same fundamental frequency (261 Hz) and were balanced in loudness and in perceived duration before the experiment. One group of NH subjects listened to unprocessed stimuli. The other two groups of NH subjects listened to the same stimuli passed through a four-channel or an eight-channel noise vocoder, designed to simulate the signal processing performed by a real CI. Subjects were presented with all possible combinations of pairs of instruments and had to estimate, for each pair, the amount of dissimilarity between the two sounds. These estimates were used to construct dissimilarity matrices, which were further analyzed using an MDS model. The model output gave, for each subject group, an optimal graphical representation of the perceptual distances between stimuli (the so-called "timbre space"). For all groups, the first two dimensions of the timbre space were strikingly similar and correlated strongly with the logarithm of the attack time and with the center of gravity of the spectral envelope, respectively. The acoustic correlate of the third dimension differed across groups but only accounted for a small proportion of the variance explained by the MDS solution. Surprisingly, CI subjects and NH subjects listening to noise-vocoded simulations gave relatively more weight to the spectral envelope dimension and less weight to the attack-time dimension when making their judgments than NH subjects listening to unprocessed stimuli. One possible reason for the relatively higher salience of spectral envelope cues in real and simulated CIs may be that the degradation of local fine spectral details produced a more stable spectral envelope across the stimulus duration. The internal representation of musical timbre for isolated musical instrument sounds was found to be similar in NH and in CI listeners. This suggests that training procedures designed to improve timbre recognition in CIs will indeed train CI subjects to use the same cues as NH listeners. Furthermore, NH subjects listening to noise-vocoded sounds appear to be a good model of CI timbre perception as they show the same first two perceptual dimensions as CI subjects do and also exhibit a similar change in perceptual weights applied to these two dimensions. This last finding validates the use of simulations to evaluate and compare training procedures to improve timbre perception in CIs.

Can monaural temporal masking asymmetry explain the transient and/or ongoing precedence effect?

Investigations of the precedence effect show that interaural differences within the first of two pairs of brief binaural sounds contribute more to lateralization than those within the second pair. The present study asked whether this phenomenon could be explained by asymmetries in monaural masking, and compared the results to a second experiment investigating the same question with the “ongoing” precedence effect. Leading and lagging stimuli were binaural pairs of 1-ms frozen noise bursts, with a 2-ms delay between pairs, and had ITDs of +500 and −500 ms, respectively. Detection thresholds for lead or lag in the presence of the other were assessed monaurally using a 4AFC task. Results showed that threshold for the lead was 12 dB better than that for the lag, on average. Ongoing stimuli were created by repeating the transient stimuli 63 times, with a new noise token on each repeat. Although the leading burst in each binaural pair contributes more to lateralization than the lagging burst, monaural thresholds for the leading bursts were not better than those for the lagging bursts. The results suggest that the transient precedence effect, but not the ongoing precedence effect, might be explained by temporal masking asymmetry. [Work supported by NIH DC01625].

Native and Novel Language Prosodic Sensitivity in English-Speaking Children with and without Dyslexia

Children with reading disability and normal reading development were compared in their ability to discriminate native (English) and novel language (Mandarin) from nonlinguistic sounds. Children's preference for native versus novel language sounds and for disyllables containing dominant trochaic versus non-dominant iambic stress patterns was also assessed. Participants included second and third grade monolingual native English speakers with reading disability (N = 18) and normal reading development (N = 18). Children selected from pairs of novel, native, and nonlinguistic sounds that was more like language. Both groups discriminated disyllabic linguistic sounds (native and novel) from nonlinguistic sounds. Both groups showed preference for the dominant English trochaic stress pattern over the non-dominant iambic stress pattern. Implications for development of prosodic sensitivity in relation to reading skills and future research are discussed.

韓国人海事英語の音声的特徴について―日本人が感じる外国語訛り―

The present study investigated pronunciation elements of Korean speakers' Maritime English that are likely to hinder successful English communication between Japanese and Korean speakers working in maritime sectors. Contrastive analyses of English, Japanese, and Korean yielded descriptions of phonological/phonetic characteristics in Korean accented English and predictions of difficulties Japanese listeners may encounter. This was followed by the analysis of Maritime English data pronounced by eight students of a maritime institute in Korea and accent judgment by Japanese listeners. The Japanese listeners were predicted not to perceive accent in sound pairs such as /l/ and /r/ since the two sounds are not distinguishable in Japanese in the first place, while it was expected voiced sounds pronounced as voiceless in certain environments due to Korean phonology would be judged accented. Also, where realization of a sound deviates from the value expected by Japanese listeners, e.g., /æ/ realized as [e], /f/ realized as [p], it was expected Japanese listeners would point out foreign accent. Although the majority of the results were consistent with what had been expected, some of the results, e.g., perception of syllable-final consonants and consonant sequences, did not match the predictions made by contrastive analysis.

Emotional sounds modulate early neural processing of emotional pictures

In our natural environment, emotional information is conveyed by converging visual and auditory information; multimodal integration is of utmost importance. In the laboratory, however, emotion researchers have mostly focused on the examination of unimodal stimuli. Few existing studies on multimodal emotion processing have focused on human communication such as the integration of facial and vocal expressions. Extending the concept of multimodality, the current study examines how the neural processing of emotional pictures is influenced by simultaneously presented sounds. Twenty pleasant, unpleasant, and neutral pictures of complex scenes were presented to 22 healthy participants. On the critical trials these pictures were paired with pleasant, unpleasant, and neutral sounds. Sound presentation started 500 ms before picture onset and each stimulus presentation lasted for 2 s. EEG was recorded from 64 channels and ERP analyses focused on the picture onset. In addition, valence and arousal ratings were obtained. Previous findings for the neural processing of emotional pictures were replicated. Specifically, unpleasant compared to neutral pictures were associated with an increased parietal P200 and a more pronounced centroparietal late positive potential (LPP), independent of the accompanying sound valence. For audiovisual stimulation, increased parietal P100 and P200 were found in response to all pictures which were accompanied by unpleasant or pleasant sounds compared to pictures with neutral sounds. Most importantly, incongruent audiovisual pairs of unpleasant pictures and pleasant sounds enhanced parietal P100 and P200 compared to pairings with congruent sounds. Taken together, the present findings indicate that emotional sounds modulate early stages of visual processing and, therefore, provide an avenue by which multimodal experience may enhance perception.

A false killer whale reduces its hearing sensitivity when a loud sound is preceded by a warning

We investigated the possibility of conditioned dampening of whale hearing thresholds when a loud sound is preceded by a warning sound. The loud sound was a tone of 20 kHz, 170 dB re. 1 μPa, 5 s. Hearing sensitivity was measured using pip-train test stimuli and auditory evoked potential recording. The same test-sound stimuli served as warning sounds. The durations of the warning sounds were varied randomly to avoid locking an anticipated conditioning effect to the timing immediately before the loud sound. When the warning sound lasted from 1 to 9 s or from 5 to 35 s prior to the loud sound, hearing thresholds before the loud sound increased, relative to the baseline, by 12.7 and 7.3 dB, respectively. When the warning sound duration varied within a range of 20 to 140 s, the threshold increase was as low as 3.0 dB. The observed hearing threshold increase was not a result of the unconditioned effect of the loud sound, like a temporary threshold shift, so it was considered to be a manifestation of a conditioned dampening of hearing when the subject anticipated the quick appearance of a loud sound, most likely to protect its hearing.