Acoustic Distance Research Articles

Individual-level cross-linguistic comparisons in Toronto Cantonese and English high vowels

Previous studies of Toronto Heritage Cantonese have suggested the lack of a similar phonological contrast in English as the source of cross-linguistic influence on the phonetic production of the /y/ vs. /u/ contrast in Cantonese. By comparing both the English and Cantonese production of the same individual speakers in spontaneous speech recordings, this study addresses Chang’s (2021) call for more bilingual studies focused on individual-level cross-linguistic interactions. Results show three distinct patterns of cross-linguistic interaction: P1) three distinct vowels, P2) Cantonese /u/ merged with English /u/, and P3) Cantonese /y/ merged with English /u/. While P1 was the most frequently occurring pattern, the occurrence of P3 exclusively among second-generation speakers, among those with lower Cantonese Production Scores, and among those with the lowest Pillai Scores suggest that cross-linguistic phonetic similarity is what drives decreased acoustic distance between /y/ and /u/ rather than direct transfer of phonological categories.

An Acoustic Sensor System to Measure Aeolian Ripple Morphology and Migration Rates.

Acoustic distance sensors have a long history of use to detect subaqueous bedforms. There have been few comparable applications for aeolian bedforms such as ripples. To address this, we developed a simple and reliable apparatus comprising a pair of distance sensors, a bracket upon which they are mounted, and a base upon which the bracket can slide. Our system relies on two Senix Corporation (Hinesburg, VT, USA), ToughSonic® model 14-TSPC-30S1-232 acoustic distance sensors: one to measure surface elevation changes (in this case, ripple morphology) and a second to measure horizontal location. The ToughSonic® vertical resolution was 0.22 mm and the horizontal scan distance was about 0.60 m with a locational accuracy of 0.22 mm. The measurement rate was 20 Hz, but we over-sampled at 1 KHz. Signal processing involves converting volts to meters, detrending the data, and removing noise. Analysis produces ripple morphologies and migration rates that conform with independent measurements. The advantages of this system relative to terrestrial laser scanning or structure from motion are described.

Dynamic acoustic vowel distances within and across dialects.

Vowels vary in their acoustic similarity across regional dialects of American English, such that some vowels are more similar to one another in some dialects than others. Acoustic vowel distance measures typically evaluate vowel similarity at a discrete time point, resulting in distance estimates that may not fully capture vowel similarity in formant trajectory dynamics. In the current study, language and accent distance measures, which evaluate acoustic distances between talkers over time, were applied to the evaluation of vowel category similarity within talkers. These vowel category distances were then compared across dialects, and their utility in capturing predicted patterns of regional dialect variation in American English was examined. Dynamic time warping of mel-frequency cepstral coefficients was used to assess acoustic distance across the frequency spectrum and captured predicted Southern American English vowel similarity. Root-mean-square distance and generalized additive mixed models were used to assess acoustic distance for selected formant trajectories and captured predicted Southern, New England, and Northern American English vowel similarity. Generalized additive mixed models captured the most predicted variation, but, unlike the other measures, do not return a single acoustic distance value. All three measures are potentially useful for understanding variation in vowel category similarity across dialects.

Geographic variation in the acoustic signals of lesser treefrogs Dendropsophus minutus (Anura, Hylidae)

Biological sound archives are a major source to investigate geographic variation in animal acoustic signals and their evolutionary drivers. The acoustic signals of anuran species with wide distribution ranges often vary geographically as a result of isolation by distance and climate amongst other factors. We examined whether the acoustic structure of call notes would vary geographically in lesser treefrogs Dendropsophus minutus using recordings from bioacoustics repositories. We also tested whether climate (mean annual temperature and annual precipitation) drive geographic variation in those signals. The acoustic distance was unrelated to geographic distance, suggesting that isolation by distance solely cannot explain geographic variation in call structure. Overall, lesser treefrogs uttered call notes with lower frequencies and bandwidths in the west of their range. In addition, frogs produced shorter call notes in hotter, wetter sites and narrow-bandwidth notes in hotter environments. We suggest that frogs produce more calls (not measured here) of shorter durations to maximize transmission and minimize the metabolic costs of calling at high air temperatures. We also suggest that hotter environments favor the propagation of lower-bandwidth calls. This study reinforces the feasibility and power of citizen science and acoustic data repositories for understanding the evolution of anuran acoustic signals.

Assessment of the localization error of radio-acoustic bug devices by means of acoustic distance measurement

Assessment of the localization error of radio-acoustic bug devices by means of acoustic distance measurement

Accuracy improvement of inner defects of cylindrical components using ultrasonic detection with modified ALOK method

The accuracy of defect localisation and its size quantification is poor in the detection of internal defects of cylindrical components using the ultrasonic Amplituden und Laufzeit Orts-Kurven (ALOK) method. The influence of acoustic beam spread is not taken into consideration in the ultrasonic ALOK method, resulting in difficulties with the precise characterisation of the defect state. To address this, the relationship between the acoustic distance, amplitude, ultrasonic frequency, size and depth of hole defects was studied. The acoustic distance curve and the amplitude curve were fitted and then the localisation model of the defect was obtained. The acoustic beam spreading angle and echo sound pressure were introduced and then the size quantification model for defects was acquired based on principal component analysis (PCA). Both the simulated and experimental results show that the modified ALOK algorithm improved the detection accuracy of the defect location and its size and the relative error of defect sizing decreased by more than 35% compared with the original algorithm.

Acoustic vowel distances within and across dialects

Regional dialects of American English exhibit variation in the phonetic realization of vowel categories. This variation leads to different degrees of phonetic vowel similarity within and across dialects. This vowel similarity has been captured by measures of formant distance and overlap in the acoustic space, typically with static formant estimates from a single timepoint in the vowel. In contrast, dialect similarity has been assessed using measures of acoustic distance over time. In the current study, dynamic measures of acoustic distance, including dynamic time warping, root mean-square distance, and generalized additive mixed effect models, were used to assess within-dialect vowel category distances and to compare these distances across dialects. The results were generally consistent across the different distance metrics, confirming their respective ability to capture acoustic vowel distance. However, the magnitude of the distances varied across dialects and vowel variables. Whereas some dialect-specific variables showed the expected patterns of within- and across-dialect similarity based on previous descriptive work, other variables did not. These mixed findings have implications for our understanding of regional dialect variation in American English, its effect on acoustic vowel similarity, and the relationship between acoustic vowel similarity and perceptual ambiguity of vowel contrasts within and across dialects.

Cross-linguistic variability in audiovisual enhancement of coronal consonants

The role of auditory perceptibility in phonological contrast is uncontroversial. In clear speech, speakers increase acoustic distance between contrastive phones, thereby improving perception. Although visual cues are also known to improve perception, it is unclear whether speakers actively enhance their speech for visual perceptibility. 20 native English and 20 native Mandarin speakers participated in a two-part production experiment. Words containing /l d n s r/ (and English /θ/) were elicited, with vowels balanced for height, backness, and rounding. Speakers first recited each word while alone in a soundproof booth. Words were then spoken for a native listener (who attempted to guess the word) over Zoom with heavily degraded audio. Audio and high-speed video were recorded. English speakers showed a significant increase in visually exaggerated articulations for /l, θ/ (but not /n, d, s, r/), including interdental and linguolabial productions with external lingual protrusion. Mandarin speakers increased their use of interdental articulation for /n, l, t, s/ (but not /r/), although lingual protrusion was limited. These results demonstrate that speakers may enhance their speech for visual over auditory perceptibility but suggest that enhancement is mediated by language-specific factors including phonological contrast and the articulatory characteristics of sounds in normal speech.

Comparing Levenshtein distance and dynamic time warping in predicting listeners’ judgments of accent distance

Listeners attend to variation in segmental and prosodic cues when judging accent strength. The relative contributions of these cues to perceptions of accentedness in English remains open for investigation, although objective accent distance measures (such as Levenshtein distance) appear to be reliable tools for predicting perceptual distance. Levenshtein distance, however, only accounts for phonemic information in the signal. The purpose of the current study was to examine the relative contributions of phonemic (Levenshtein) and holistic acoustic (dynamic time warping) distances from the local accent to listeners’ accent rankings for nine non-local native and nonnative accents. Listeners (n = 52) ranked talkers on perceived distance from the local accent (Midland American English) using a ladder task for three sentence-length stimuli. Phonemic and holistic acoustic distances between Midland American English and the other accents were quantified using both weighted and unweighted Levenshtein distance measures, and dynamic time warping (DTW). Results reveal that all three metrics contribute to perceived accent distance, with the weighted Levenshtein slightly outperforming the other measures. Moreover, the relative contribution of phonemic and holistic acoustic cues was driven by the speaker's accent. Both nonnative and non-local native accents were included in this study, and the benefits of considering both of these accent groups in studying phonemic and acoustic cues used by listeners is discussed.

Processing of acoustic and phonological information of lexical tones at pre-attentive and attentive stages

ABSTRACT While Mismatch Negativity (MMN) and P300 have been found to correlate with the processing of acoustic and phonological information involved in speech perception, there is controversy surrounding how these two components index acoustic and/or phonological processing at pre-attentive and attentive stages. The current study employed both passive and active oddball paradigms to examine neural responses to lexical tones at the two stages in Cantonese speakers, using the paradigm of categorical perception (CP) where the between- and within-category deviants share the same acoustic distance from the standard but differ in the involvement of phonological information. We failed to observe a CP effect in P300, which might indicate that this component doesn’t necessarily index phonological processing, while MMN does, as reflected by the finding of a greater MMN amplitude elicited from the between-category than within-category deviant. Nevertheless, phonological processing might be overridden by acoustic processing among participants who were sensitive to pitch.

Threat vocalisations are acoustically similar between humans (Homo sapiens) and chimpanzees (Pan troglodytes)

ABSTRACT In behavioural contexts like fighting, eating, and playing, acoustically distinctive vocalisations are produced across many mammalian species. Such expressions may be conserved in evolution, pointing to the possibility of acoustic regularities in the vocalisations of phylogenetically related species. Here, we test this hypothesis by comparing the degree of acoustic similarity between human and chimpanzee vocalisations produced in 10 similar behavioural contexts. We use two complementary analysis methods: Pairwise acoustic distance measures and acoustic separability metrics based on unsupervised learning algorithms. Cross-context analysis revealed that acoustic features of vocalisations produced when threatening another individual were distinct from other types of vocalisations and highly similar across species. Using a multimethod approach, these findings demonstrate that human vocalisations produced when threatening another person are acoustically similar to chimpanzee vocalisations in the same situation as compared to other types of vocalisations, likely reflecting a phylogenetically ancient vocal signalling system.

Bilingual phonological contrast perception: The influence of Quanzhou Southern Min on Mandarin non-sibilant fricative discrimination.

This study explores the discrimination of Mandarin non-sibilant fricatives by bilingual speakers (N = 40) of Quanzhou Southern Min (L1) and Mandarin (L2) in different phonological contexts, including rounded vowels and the glide [w]. The results of the ABX discrimination task indicate significant contextual effects of the following sound, in line with predictions based on the Perceptual Assimilation model (PAM) [Best (1995). J. Phon. 20(3), 305-330]. Additionally, the observed result could not be fully explained by the acoustic distance between stimuli, and discrimination ability was better for speakers with more exposure to and use of Mandarin.

ASBL: low-cost, small-sized AUV remote guidance method and experimental verification

The low-cost, small-sized autonomous underwater vehicle (AUV) is the preferred carrier for seabed operations. As all know, the inertial navigation system (INS) error drifts over time. Three or more seafloor datum signals are required when error-correcting the INS using the long baseline (LBL). Typically, a seafloor datum has an acoustic ranging capability of 15 km. However, the positioning ability of the conventional LBL is limited and cannot play the role of remote guidance when there is only a single datum. The paper proposes the Acoustic Synthetic Baseline (ASBL) positioning technology, which can achieve target positioning through multi-frame acoustic distance estimates between the measured target and the underwater datum. Firstly, the positioning principle of the ASBL is introduced, and the error distribution is analyzed in the paper. Secondly, a small-sized AUV is used to carry out the verification on the lake test, and the result shows that the ASBL positioning technology can play a guiding role. According to the statistics of the positioning results, the detection probability of less than 5% positioning error can reach more than 83%. The ASBL technology can reduce the dependence on the number of seafloor datums that convenience and operation efficiency can improve only by a single datum.

Comparing segmental and suprasegmental features in speaker gender perception: An acoustic distance approach

Segmental (e.g., articulation) and suprasegmental (e.g., intonation) speech features provide meaningful perceptual cues to speaker gender. Yet, the relative perceptual importance of these features remains poorly understood. Further, proposed methods for quantifying these features often require labor-intensive measurement by human judges. This study used an acoustic-only method to quantify segmental and suprasegmental features among 60 speakers with varied gender identities (e.g., non-binary, transgender and cisgender men and women) and compared these acoustic measures to human perceptual judgements of speaker gender. Thirty listeners rated confidence in speaker gender and masculinity/femininity for each speaker. To obtain acoustic distance among speakers, three conditions were created that manipulated which acoustic features were present in the speech utterances. Acoustic distance was calculated in each of the three conditions between each speaker and a cisgender man and woman who were perceptually rated as most gender prototypical. Acoustic distances for the three conditions were fit to regression models to determine which was most predictive of listeners’ perceptual judgements. Both segmental and intonation features predicted perceptual measures. However, segmental cues better explained listener’s ratings, suggesting their greater perceptual weighting in listeners’ judgements of speaker gender.

Acoustic distance effect on the perception of sibilants mergers between retroflexes and alveolars in Taiwan Mandarin

Studies in speech production and perception have found a tight link between the two processes. Sound properties in speakers' production repertoire strongly influence their perceptual spaceand exposure to another variant also shifts speech patterns in shadowing tasks. This suggests that diachronic sound change might be a result of it. Therefore, we tested whether categorical perception of sibilants is influenced by acoustic distance in the production of ongoing sibilants mergers in Taiwan Mandarin, where retroflexes are merging towards alveolars. Twenty-three native speakers produced 46 mono- or disyllabic Tone 1 words with onsets of /ts/, /ʈʂ/, /tsh/, /ʈʂh/, /s/, and /ʂ/, listened to 23 eight-step continuums of synthesized sibilants from retroflexes to alveolars pre-appended to vowels and codas, and answered a sociolinguistic questionnaire. As predicted, closer acoustic distances between categories predicted more high-CoG stimuli to be identified as retroflexes (more tolerance for high-frequency retroflexes). Step, sound, and social effects were significant. Sibilants' frequencies were lower than previously reported. Overall, this suggests that sibilant mergers diffuse to speakers with closer acoustic distances first, and the categories will collapse on language level in production before perception. They spread among speakers asynchronously and variably, depending on dialectal background and social attitude as well.

Design of Intelligent Ultrasonic Guided Vehicle

Due to the requirement of the development of the times, all walks of life require more and more intelligence, so more and more intelligent mobile machines and equipment are popularized. Compared with traditional equipment, smart cars have better mobility, safety and practicality. However, nowadays, domestic follow-up equipment generally exists in various highly specialized venue environments, which have certain environmental requirements, or track following camera cars in other specific sites, which have certain environmental requirements. There is no follow-up equipment or personal products for public places with complex situations, such as supermarkets, airports, railway stations, etc. This paper designs an intelligent vehicle based on Arduino programming, which is simple and practical, highly modular and highly portable. The smart car with low design cost, simple and mature technology and high portability can be used in work and ordinary life without manual operation. The smart car can use Arduino Nano, acoustic distance measurement module, motor, etc. in this design to achieve the positioning of specific targets and calculate the distance, including forward and backward, turning, At the same time, according to the feedback information, we can adjust the speed and turn behavior to track the target. Using mature ultrasonic ranging technology, chip, accurate positioning control algorithm, this simple, cheap and practical intelligent tracking car is designed

Semi-Automatic Defect Distinction of PAUT for High Strength Steel Corner Structure

In this study, A GCN distinction network is proposed to identify the defect status of steel corner structures. In this defect determination method, the detected S-scan data is converted into A-scan by Doppler software to form a two-dimensional detection matrix, and the two dimensions are deflection angle stepping and sampling point on the acoustic distance respectively. GCN needs data node relations for GCN’s adjacent matrix, which concludes the shape of the sample and the reflection information and the structure of acoustic beam direction. The conventional inverse and threshold method are introduced in order to enhance classification performance. According to the node and the adjacency matrix relationship between nodes of affiliation and node sampling value automatically set the node label, The GCN model is constructed. Due to the characteristics of GCN, the beam length in the adjacent matrix cannot be changed again in the application test. Except for the detection model of Beamtool software, all other data processes and distinction are carried out automatically. In this study, the PAUT of low-alloy steel (30CrMnSi) was carried out by the PHASCAN II detector, to verify the effectiveness of the research method through natural wave and defect echo experiments which will be confused to distinguish.

Vowel convergence does not affect auditory speaker discriminability in humans and machine in a case study on Swiss German dialects

In this study, we examined whether the convergence in interlocutors’ vowel acoustics leads to decreasing discriminability between interlocutors’ voices. Ten pairs of Grison and Zürich German speakers produced lexical items before and after dialogue interactions with evidence of vowel convergence in post-dialogue productions. In Experiment 1, native and non-native Swiss German listeners discriminated pairs of speakers whose speech was obtained pre- and post-dialogue. Results showed that listeners’ sensitivity (A’) was higher for native than non-native listeners, but comparable for pre- and post-dialogue recordings. The observed negative correlation between voice discrimination and the acoustic distance in formant space was mainly driven by a single speaker pair. In Experiment 2, the speaker recognition performance of an i-vector-based software was compared in pre- and post-dialogue speech. Results revealed no difference in the system performance between the two conditions. The findings suggest that vowel convergence does not compromise voice discriminability under the given experimental conditions.

Acoustic Distance Measurement with Practical Ambient Noise Reduction Using Difference Signals among Adjacent 3ch Observations

Acoustic Distance Measurement with Practical Ambient Noise Reduction Using Difference Signals among Adjacent 3ch Observations

Auditory distance perception by blind and sighted participants for both within- and beyond-reach sources.

This study aimed to test the hypothesis that associates blindness with a reduced ability to judge the absolute distance from sound sources. Our working hypotheses were the following: (a) Within reach, a blind subject will be able to make up for the lack of vision using proprioceptive information to calibrate the acoustic distance perception cues. (b) As the source becomes unreachable, blind people will show greater biases since, out of reach, the proposed mechanism for calibration could not be used. To approach these topics, we carried out a series of auditory distance experiments in which we asked sighted and blind participants to report their distance estimates verbally or by reaching the sound source. Within-reach results showed that blind participants performed better than (reaching) or similar to (verbal report) the sighted. The verbal report results showed similar biases between both groups. However, blind participants had more compressive responses than the sighted. Furthermore, blind participants showed more biased responses in the far field than in the peripersonal space, while sighted participants showed similar biases regardless of distance. Our results strongly suggest that the blind can calibrate their distance estimations through the use of proprioceptive spatial information. (PsycInfo Database Record (c) 2022 APA, all rights reserved).