Acoustic Perception Research Articles

Acoustic perceptions of vessel fitness in southern Africa

The acoustic properties of objects found in archaeological contexts have seen little attention because they are seldom found intact. Nevertheless, sound is quality of objects that is of tremendous significance during both their manufacture and use. In this article, the authors examine how the acoustic properties of ceramic vessels influence the perception of their fitness for use. Grounded in how sound cues correlate to visual, tactile and olfactory measures of vessel fitness in an ethnographic context, they focus on detecting perceptible sonic differences between damaged and undamaged vessels produced by Zulu and Swazi potters in southern Africa. The article demonstrates how sound is a key quality of vessel ‘strength’ that both potters and clientele use to gauge functional and social suitability. We show that studies of fabric characteristics, such as fissures and voids, in addition to fabric composition provide a means to infer the acoustic properties of archaeological pottery and evaluate the significance of sound in past valuations of vessel fitness. Archaeological discussions of materiality can explore how social valuations of vessel fitness are accessible through studies of the functional properties of ceramics that consider human sensory experience.

Discrimination of acoustically similar conspecific and heterospecific vocalizations by black-capped chickadees (Poecile atricapillus).

Chickadees produce a multi-note chick-a-dee call in multiple socially relevant contexts. One component of this call is the D note, which is a low-frequency and acoustically complex note with a harmonic-like structure. In the current study, we tested black-capped chickadees on a between-category operant discrimination task using vocalizations with acoustic structures similar to black-capped chickadee D notes, but produced by various songbird species, in order to examine the role that phylogenetic distance plays in acoustic perception of vocal signals. We assessed the extent to which discrimination performance was influenced by the phylogenetic relatedness among the species producing the vocalizations and by the phylogenetic relatedness between the subjects' species (black-capped chickadees) and the vocalizers' species. We also conducted a bioacoustic analysis and discriminant function analysis in order to examine the acoustic similarities among the discrimination stimuli. A previous study has shown that neural activation in black-capped chickadee auditory and perceptual brain regions is similar following the presentation of these vocalization categories. However, we found that chickadees had difficulty discriminating between forward and reversed black-capped chickadee D notes, a result that directly corresponded to the bioacoustic analysis indicating that these stimulus categories were acoustically similar. In addition, our results suggest that the discrimination between vocalizations produced by two parid species (chestnut-backed chickadees and tufted titmice) is perceptually difficult for black-capped chickadees, a finding that is likely in part because these vocalizations contain acoustic similarities. Overall, our results provide evidence that black-capped chickadees' perceptual abilities are influenced by both phylogenetic relatedness and acoustic structure.

Interview

interview

An Adaptive Neural Mechanism for Acoustic Motion Perception with Varying Sparsity.

Biological motion-sensitive neural circuits are quite adept in perceiving the relative motion of a relevant stimulus. Motion perception is a fundamental ability in neural sensory processing and crucial in target tracking tasks. Tracking a stimulus entails the ability to perceive its motion, i.e., extracting information about its direction and velocity. Here we focus on auditory motion perception of sound stimuli, which is poorly understood as compared to its visual counterpart. In earlier work we have developed a bio-inspired neural learning mechanism for acoustic motion perception. The mechanism extracts directional information via a model of the peripheral auditory system of lizards. The mechanism uses only this directional information obtained via specific motor behaviour to learn the angular velocity of unoccluded sound stimuli in motion. In nature however the stimulus being tracked may be occluded by artefacts in the environment, such as an escaping prey momentarily disappearing behind a cover of trees. This article extends the earlier work by presenting a comparative investigation of auditory motion perception for unoccluded and occluded tonal sound stimuli with a frequency of 2.2 kHz in both simulation and practice. Three instances of each stimulus are employed, differing in their movement velocities–0.5°/time step, 1.0°/time step and 1.5°/time step. To validate the approach in practice, we implement the proposed neural mechanism on a wheeled mobile robot and evaluate its performance in auditory tracking.

Assessing the distinctiveness of phonological features in word recognition: Prelexical and lexical influences

Phonological features have been shown to differ from one another in their perceptual weight during word recognition. Here, we examine two possible sources of these asymmetries: bottom-up acoustic perception (some featural contrasts are acoustically more different than others), and top-down lexical knowledge (some contrasts are used more to distinguish words in the lexicon). We focus on French nouns, in which voicing mispronunciations are perceived as closer to canonical pronunciations than both place and manner mispronunciations, indicating that voicing is less important than place and manner for distinguishing words from one another. We find that this result can be accounted for by coalescing the two sources of bias. First, using a prelexical discrimination paradigm, we show that manner contrasts have the highest baseline perceptual salience, while there is no difference between place and voicing. Second, using a novel method to compute the functional load of phonological features, we show that the place feature is most often recruited to distinguish nouns in the French lexicon, while voicing and manner are exploited equally often.

Identifying the Quiet Areas of a Small Urban Setting: The Case of Mytilene

<p>The aim of this study is to achieve a greater insight regarding quiet areas in agglomerations and contribute to their identification. The small urban setting of Mytilene located in the island of Lesvos (North Aegean, Greece), was the case study of this research. The need to control and manage environmental noise has led to the implementation of legislation that in many cases overlooks the acoustic perception of individuals. Due to the fact that noise management efforts along with the promotion of quietness in agglomerations, concerns primarily the residents of the city under consideration, it was essential to practically involve them in the decision making process.  Based on citizen science contribution, a number of “places” were highlighted. The “places” mentioned from this procedure were checked by means of acoustic measurements, concerning the noise levels that occurred within the 24h period. A novel method regarding the duration, repetition, check spot and the positioning of measurement was used, in order to calculate the day, evening and night period’s noise levels (L<sub>den</sub>). A performance matrix was then created in order to compare the results, in relation to acoustical, functional and visual criteria. Furthermore, in order to evaluate all the potential Quiet Areas in pairwise comparisons, an Analytical Hierarchy Process (AHP) was implemented. The provision of quietness, as a direct ecosystem service, is a major indicator of environmental quality. Additionally, the way that city inhabitants perceive their acoustic surroundings could determine the character of the landscape along with the quality of the soundscape and define the meaning of quietness that still remains vague.      </p>

Individual differences in the production of nasal coarticulation and perceptual compensation

The current study investigates correlations between individual differences in the production of nasal coarticulation and patterns of perceptual compensation in American English. A production study (Experiment 1) assessed participants’ nasal coarticulation repertoires by eliciting productions of CVC, CVN and NVN words. Stimuli for two perception tasks were created by cross-splicing oral vowels (from C_C words), nasal vowels (from C_N words), and hypernasal vowels (from N_N words) into C_C, C_N, and N_N consonant contexts. Stimuli pairs were presented to listeners in a paired discrimination task (Experiment 2), where similarity of vowels was assessed, and a nasality ratings task (Experiment 3), where relative nasalization of vowels was judged. In the discrimination task, individual differences in produced nasal coarticulation predicted patterns of veridical acoustic perception. Individuals who produce less extensive anticipatory nasal coarticulation exhibit more veridical acoustic perception (indicating less compensation for coarticulation) than individuals who produce greater coarticulatory nasality. However, in the ratings task, listeners’ produced nasal coarticulation did not predict perceptual patterns. Rather, more veridical perceptual response patterns were observed across participants in context-inappropriate coarticulatory conditions, i.e., for hypernasal vowels in C_N contexts (e.g. bẽ̃n) and nasal vowels in N_N contexts (e.g. mẽn). The results of this study suggest a complex and multifaceted relationship between representations used to produce and perceive speech.

Hearing rock art landscapes: a survey of the acoustical perception in the Sierra de San Serván area in Extremadura (Spain)

ABSTRACTThis article focuses on the augmented audibility of distant sounds that is experienced in some rock art sites. We propose a method developed in acoustical physics to measure this acoustic phenomenon, the Transmission Loss (TL) analysis. We have assessed the validity of the method in our study area, the Sierra de San Serván in the region of Extremadura (Spain), an area where from the hundreds of shelters only sixty five were decorated with Schematic art during prehistory. The analysis undertaken in it has provided unequivocal data that indicate that augmented audibility of distant sounds seemed to be a factor considered by the prehistoric artists for the selection of rock art shelters to paint in. This is especially made clear when a comparison between the results obtained in shelters with rock art and others in the same area without it is made. From all the sites one stands out, that of Las Palomas 2, with the best results. This site is also special for other features that no other site in the area has in terms of difficult access and high visibility.

Acoustic and Auditory Perception Effects of the Voice Therapy Technique Finger Kazoo in Adult Women

This study aimed to verify and to correlate acoustic and auditory-perceptual measures of glottic source after the performance of finger kazoo (FK) technique. This is an experimental, cross-sectional, and qualitative study. We made an analysis of the vowel [a:] in 46 adult women with neither vocal complaints nor laryngeal alterations, through the Multi-Dimensional Voice Program Advanced and RASATI scale, before and immediately after performing three series of FK and 5 minutes after a period of silence. Kappa, Friedman, Wilcoxon, and Spearman tests were used. We found significant increase in fundamental frequency, reduction of amplitude variation, and degree of sub-harmonics immediately after performing FK. Positive correlations were measures of frequency and its perturbation, measures of amplitude, of soft phonation index, of degree and number of unvoiced segments with aspects of RASATI. Negative correlations were voice turbulence index, measures of frequency and its perturbation, and measures of soft phonation index with aspects of RASATI. There was fundamental frequency increase, within normal limits, and reduction of acoustic measures related to presence of noise and instability. In general, acoustic measures, suggestive of noise and instability, were reduced according to the decrease of perceptive-auditory aspects of vocal alteration. It shows that both instruments are complementary and that the acoustic vocal effect was positive.

Perception of music dynamics in concert hall acoustics.

Dynamics is one of the principal means of expressivity in Western classical music. Still, preceding research on room acoustics has mostly neglected the contribution of music dynamics to the acoustic perception. This study investigates how the different concert hall acoustics influence the perception of varying music dynamics. An anechoic orchestra signal, containing a step in music dynamics, was rendered in the measured acoustics of six concert halls at three seats in each. Spatial sound was reproduced through a loudspeaker array. By paired comparison, naive subjects selected the stimuli that they considered to change more during the music. Furthermore, the subjects described their foremost perceptual criteria for each selection. The most distinct perceptual factors differentiating the rendering of music dynamics between halls include the dynamic range, and varying width of sound and reverberance. The results confirm the hypothesis that the concert halls render the performed music dynamics differently, and with various perceptual aspects. The analysis against objective room acoustic parameters suggests that the perceived dynamic contrasts are pronounced by acoustics that provide stronger sound and more binaural incoherence by a lateral sound field. Concert halls that enhance the dynamics have been found earlier to elicit high subjective preference.

Airborne Acoustic Perception by a Jumping Spider

Jumping spiders (Salticidae) are famous for their visually driven behaviors [1]. Here, however, we present behavioral and neurophysiological evidence that these animals also perceive and respond to airborne acoustic stimuli, even when the distance between the animal and the sound source is relatively large (∼3 m) and with stimulus amplitudes at the position of the spider of ∼65 dB sound pressure level (SPL). Behavioral experiments with the jumping spider Phidippus audax reveal that these animals respond tolow-frequency sounds (80Hz; 65 dB SPL) by freezing-a common anti-predatory behavior characteristic of an acoustic startle response. Neurophysiological recordings from auditory-sensitive neural units in the brains of these jumping spiders showed responses to low-frequency tones (80Hz at ∼65 dB SPL)-recordings that also represent the first record of acoustically responsive neural units in the jumping spider brain. Responses persisted even when the distances between spider and stimulus source exceeded 3m and under anechoic conditions. Thus, these spiders appear able to detect airborne sound at distances in the acoustic far-field region, beyond the near-field range often thought to bound acoustic perception in arthropods that lack tympanic ears (e.g., spiders) [2]. Furthermore, direct mechanical stimulation of hairs on the patella of the foreleg was sufficient to generate responses in neural units that also responded to airborne acoustic stimuli-evidence that these hairs likely play a role in the detection of acoustic cues. We suggest that these auditory responses enable the detection of predators and facilitate an acoustic startle response. VIDEO ABSTRACT.

Vocal fry in realistic speech: Acoustic characteristics and perceptions of vocal fry in spontaneously produced and read speech

There has been a great deal of recent interest in vocal fry, both in production and perception. However, much of the scientific literature that has used naturally produced fry has focused on speech elicited through reading, rather than spontaneous speech. The current study compares reading with spontaneous speech elicited in various ways for both male and female speakers, recorded in dyads. The speakers were asked to teach their partner information, give instructions, and describe their qualifications for a scholarship, with reading controls for each task. Surprisingly, we found more vocal fry (in both proportion of words and words/duration) for men than women. Men differed in the amount of fry across task types. Interactions of speaker sex, task type, and fry were examined for measures of F0, pitch range, intensity level, jitter, shimmer, and HNR. Listener perceptions of speech with and without vocal fry were also obtained. Task type affected listener perceptions of speech with vocal fry. Vocal fry in spontaneously produced speech seems to differ from fry in speech produced during reading, in quantity, acoustics, and listener perceptions. Additionally, acoustic measures suggest that vocal fry may be intimately tied to decreased vocal effort across task types and speaker sex.

Impact of architectural variables on acoustic perception in concert halls

Acoustic perception in concert halls has been a topic of research of great interest over the last century. It has been studied through physical and subjective parameters. Nevertheless, a concert in an auditorium is a multi-sensorial experience; so that the acoustic perception may be influenced by other non-acoustical attributes. Therefore, the aim of the present study was to analyze whether architectural variables (visual component) affect acoustic perception in concert halls and quantify this influence. This analysis was carried out implementing the Semantic Differential method and differentiating among experts and non-experts users. A total of 310 subjects assessed in situ 17 concert halls. Results showed that acoustic perception was influenced by the visual component, and acoustic parameters had an influence on architecture as well. However, when separating both groups, it was found that experts were able to isolate acoustic variables from architecture when evaluating the sound quality of a venue.

Tonotopic and Field-Specific Representation of Long-Lasting Sustained Activity in Rat Auditory Cortex.

Cortical information processing of the onset, offset, and continuous plateau of an acoustic stimulus should play an important role in acoustic object perception. To date, transient activities responding to the onset and offset of a sound have been well investigated and cortical subfields and topographic representation in these subfields, such as place code of sound frequency, have been well characterized. However, whether these cortical subfields with tonotopic representation are inherited in the sustained activities that follow transient activities and persist during the presentation of a long-lasting stimulus remains unknown, because sustained activities do not exhibit distinct, reproducible, and time-locked responses in their amplitude to be characterized by grand averaging. To address this gap in understanding, we attempted to decode sound information from densely mapped sustained activities in the rat auditory cortex using a sparse parameter estimation method called sparse logistic regression (SLR), and investigated whether and how these activities represent sound information. A microelectrode array with a grid of 10 × 10 recording sites within an area of 4.0 mm × 4.0 mm was implanted in the fourth layer of the auditory cortex in rats under isoflurane anesthesia. Sustained activities in response to long-lasting constant pure tones were recorded. SLR then was applied to discriminate the sound-induced band-specific power or phase-locking value from those of spontaneous activities. The highest decoding performance was achieved in the high-gamma band, indicating that cortical inhibitory interneurons may contribute to the sparse tonotopic representation in sustained activities by mediating synchronous activities. The estimated parameter in the SLR decoding revealed that the informative recording site had a characteristic frequency close to the test frequency. In addition, decoding of the four test frequencies demonstrated that the decoding performance of the SLR deteriorated when the test frequencies were close, supporting the hypothesis that the sustained activities were organized in a tonotopic manner. Finally, unlike transient activities, sustained activities were more informative in the belt than in the core region, indicating that higher-order auditory areas predominate over lower-order areas during sustained activities. Taken together, our results indicate that the auditory cortex processes sound information tonotopically and in a hierarchical manner.

Pervasive approach to acoustic source perception in horizontal plane

Summary Acoustic is key facet in terms of sound related experiments on human subject. Perception plays an important role in performance of human under various environmental conditions. Perception of acoustic source accurately has advantages for performance of work by human. In this work acoustic source perception by human in horizontal plane is illustrated. For experiments to be performed in horizontal plane eleven Bluetooth enabled speaker (BES) tagged 1–11 numbers were placed evenly at 30° in a circular outline and input to BES was controlled with the help of computer. The sound level meter was used to check the accuracy of tagged BES. The experiment on sound perception was performed on 20 subjects (10 male, 10 female, 15 subjects aged 18–35, 5 subjects above 50), all of them have no issue of abnormal or defective hearing. The subjects have never participated in this type of experiment previously and provided with response measurement sheet (RMS). Two set of acoustic source perception experiments were designed for this study. In first experiment, buzz sound was used as acoustic source with low fixed frequency (LFF) of 2000 Hz and high fixed frequency (HFF) of 17 kHz. The experiments were performed for both LFF and HFF. Initially, set of LFF experiment was performed. The BES was sounded in arbitrary order, with each stimulus for 4 second. After each stimulus, subject was asked to point at BES from where sound is perceived and clearly writes the number of BES on the RMS provided. Similar set of HFF experiment was performed and recorded in RMS. In the second experiment white noise was added at same fixed frequency and similar task was repeated by the subjects and recorded in RMS. The data recorded from the two set of experiments was compared and analyzed. The results show the perception of acoustic source in horizontal plane is effected by the addition of white noise to the LFF and HFF.

Voice Quality After a Semi-Occluded Vocal Tract Exercise With a Ventilation Mask in Contemporary Commercial Singers: Acoustic Analysis and Self-Assessments

The current study aimed at investigating the immediate effects of a semi-occluded vocal tract exercise with a ventilation mask in a group of contemporary commercial singers. A randomized controlled study was carried out. Thirty professional or semi-professional singers with no voice complaints were randomly divided into two groups on recruitment: an experimental group and a control group. The same warm-up exercise was performed by the experimental group with an occluded ventilation mask placed over the nose and the mouth and by the control group without the ventilation mask. Voice was recorded before and after the exercise. Acoustic and self-assessment analysis were accomplished. The acoustic parameters of the voice samples recorded before and after training were compared, as well as the parameters' variations between the experimental and the control group. Self-assessment results of the experimental and the control group were compared too. Significant changes after the warm-up exercise included jitter, shimmer, and singing power ratio (SPR) in the experimental group. No significant changes were recorded in the control group. Significant differences between the experimental and the control group were found for ΔShimmer and ΔSPR. Self-assessment analysis confirmed a significantly higher phonatory comfort and voice quality perception for the experimental group. The results of the present study support the immediate advantageous effects on singing voice of a semi-occluded vocal tract exercise with a ventilation mask in terms of acoustic quality, phonatory comfort, and voice quality perception in contemporary commercial singers. Long-term effects still remain to be studied.

Evaluating a visual-acoustic simulation for wind park assessment

The implementation of wind parks often fails due to lack of public acceptance. Visual-acoustic landscape simulations of wind parks offer a potential instrument for public participation, allowing experiencing the visual and the acoustic landscape impact. However, before such simulations can be implemented in practice, they need to be validated.In this article, we develop and apply an approach to evaluate visual-acoustic simulations for assessing wind park perceptions. The approach compares whether simulations generate similar reactions of respondents as recordings of the same environments. The survey participants made a visual and an acoustic assessment of the landscape represented by recordings and by simulations.The results show that there was nearly no difference in the rating of the annoyance of wind turbine noise between the recordings and the simulation. With regard to the visual landscape assessment the ratings based on the simulations were lower than the ones based on the recordings. The approach indicates aspects of the simulation that differ compared to the recording, such as coherent coloring and animation of landscape elements. The rating differences between the recordings and the simulations of both, the visual and the acoustic perception have to be considered when using the simulations for further studies.Overall, the described approach was successfully applied and contributes to validity testing methods. However, this is a preliminary and exploratory study. A complete test of validity should compare the simulations to the actual environment, which should be further studied.

Does surprise enhancement or repetition suppression explain visual mismatch negativity?

A long tradition of electrophysiological studies, using oddball sequences, showed that the neural responses to a given stimulus differ when their presentation occurs frequently (standards) as compared to rare, infrequent presentations (deviants). This difference, originally described in acoustic perception, can also be detected in the visual modality and is termed as visual mismatch negativity (vMMN). Also, a large number of studies detected the reduction of the neuronal response after the repetition of a given stimulus (repetition suppression - RS) and it was suggested that RS is the major mechanism of MMN, an explanation currently also supported by animal studies. However, human studies have proposed that a surprise-related response enhancement for the deviant stimuli might also underlie vMMN. Therefore, the aim of the current study was to disentangle which neural mechanism explains vMMN better: the surprise related response enhancement for the presentation of rare deviants or the RS related to the frequent presentation of the standards. Since the MMN depends strongly on the applied categories, we tested the neural mechanisms of vMMN for different stimulus categories (faces, chairs, real and false characters) using a visual oddball paradigm. We found significant vMMN for every stimulus category. Interestingly, the neural mechanisms behind vMMN were found to be category dependent (assuming no cross-adaptation effects): for faces and chairs it was largely driven by RS, whereas for real and false characters it was mainly due to surprise-related changes.

To Hear Ergo To See, or On the Acoustic Specifi city of the Ceremonial Performances of Amur Peoples

The present article presents the analyses acoustic components of traditional culture of the peoples living in the South of the Far East Region. Recognizing the significance of performance text as a compound system of choreog-raphy, stage design and acoustic component, the author emphasizes the performance basis of the ritual syncretism. The author demonstrates that the roots of the Amur acoustic world perception should be sought for in the system of visual, emotional and sensual, kinetic components associated with the imitation nature of the Amur ceremonial performances. The research develops the idea that due to syncretic consciousness, the acoustic layer of Amur rituals did not just provide the audience with some audial impressions, but also translated them into visual, thereby proving the audiovisual unity of a tribal man's consciousness.

Alteraciones en la voz de las pacientes con anorexia nerviosa restrictiva: un estudio piloto

This article is about the tone of voice (acoustic perception) in patients with restrictive anorexia nervosa (AN-R). Our goal was to study whether or not there is an alteration of the tone in restrictive anorexia nervosa when the disease has started in the puberty. The total sample consisted of 148 subjects divided in two groups: control (n=102) and AN-R (n=46). The voice's fundamental frequencies (F0) were determined based on the repetition of two phonemes (“a” and “i”) and measured by a microphone Plantonic 300 and a digital recorder. We analyzed the voice's F0 using Praat software. We present the first data for the normal range of the F0 in Spanish healthy women from 9 to 17 years old who were Spanish native speakers. Finally, we show a comparison of data between AN-R patients and control group.