Acoustic Experience Research Articles

Development of synaptic fidelity and action potential robustness at an inhibitory sound localization circuit: effects of otoferlin‐related deafness

Sound localization involves information analysis in the lateral superior olive (LSO), a conspicuous nucleus in the mammalian auditory brainstem. LSO neurons weigh interaural level differences (ILDs) through precise integration of glutamatergic excitation from the cochlear nucleus (CN) and glycinergic inhibition from the medial nucleus of the trapezoid body (MNTB). Sound sources can be localized even during sustained perception, an accomplishment that requires robust neurotransmission. Virtually nothing is known about the sustained performance and the temporal precision of MNTB-LSO inputs after postnatal day (P)12 (time of hearing onset) and whether acoustic experience guides development. Here we performed whole-cell patch-clamp recordings to investigate neurotransmission of single MNTB-LSO fibres upon sustained electrical stimulation (1-200Hz/60s) at P11 and P38 in wild-type (WT) and deaf otoferlin (Otof) knock-out (KO) mice. At P11, WT and KO inputs performed remarkably similarly. In WTs, the performance increased drastically between P11 and P38, e.g. manifested by an 8 to 11-fold higher replenishment rate (RR) of synaptic vesicles and action potential robustness. Together, these changes resulted in reliable and highly precise neurotransmission at frequencies ≤100Hz. In contrast, KO inputs performed similarly at both ages, implying impaired synaptic maturation. Computational modelling confirmed the empirical observations and established a reduced RR per release site for P38 KOs. In conclusion, acoustic experience appears to contribute massively to the development of reliable neurotransmission, thereby forming the basis for effective ILD detection. Collectively, our results provide novel insights into experience-dependent maturation of inhibitory neurotransmission and auditory circuits at the synaptic level. KEY POINTS: Inhibitory glycinergic inputs from the medial nucleus of the trapezoid body (MNTB) to the lateral superior olive (LSO) are involved in sound localization. This brainstem circuit performs reliably throughout life. How such reliability develops is unknown. Here we investigated the role of acoustic experience on the functional maturation of MNTB-LSO inputs at juvenile (postnatal day P11) and young adult ages (P38) employing deaf mice lacking otoferlin (KO). We analysed neurotransmission at single MNTB-LSO fibres in acute brainstem slices employing prolonged high-frequency stimulation (1-200Hz/60s). At P11, KO inputs still performed normally, as manifested by normal synaptic attenuation, fidelity, replenishment rate, temporal precision and action potential robustness. Between P11 and P38, several synaptic parameters increased substantially in wild-type mice, collectively resulting in high-fidelity and temporally precise neurotransmission. In contrast, maturation of synaptic fidelity was largely absent in KOs after P11. Collectively, reliable neurotransmission at inhibitory MNTB-LSO inputs develops under the guidance of acoustic experience.

A prenatal acoustic signal of heat affects thermoregulation capacities at adulthood in an arid-adapted bird

Understanding animal physiological adaptations for tolerating heat, and the causes of inter-individual variation, is key for predicting climate change impacts on biodiversity. Recently, a novel mechanism for transgenerational heat adaptation was identified in a desert-adapted bird, where parents acoustically signal hot conditions to embryos. Prenatal exposure to “heat-calls” adaptively alters zebra finch development and their thermal preferences in adulthood, suggesting a long-term shift towards a heat-adapted phenotype. However, whether such acoustic experience improves long-term thermoregulatory capacities is unknown. We measured metabolic rate (MR), evaporative water loss (EWL) and body temperature in adults exposed to a stepped profile of progressively higher air temperatures (Ta) between 27 and 44 °C. Remarkably, prenatal acoustic experience affected heat tolerance at adulthood, with heat-call exposed individuals more likely to reach the highest Ta in morning trials. This was despite MR and EWL reaching higher levels at the highest Ta in heat-call individuals, partly driven by a stronger metabolic effect of moderate activity. At lower Ta, however, heat-call exposed individuals had greater relative water economy, as expected. They also better recovered mass lost during morning trials. We therefore provide the first evidence that prenatal acoustic signals have long-term consequences for heat tolerance and physiological adaptation to heat.

My experience at threshold and the consultation process

I had the great opportunity to take part in the Acoustical Society of America’s (ASA) 2021Summer Undergraduate Research or Internship Experience in Acoustics (SURIEA) Program. The program was designed for underrepresented minority groups in order to introduce them to the field of acoustics. After a two-week crash course I was able to experience what it was like working in an architectural acoustic consultation firm and learn the extensive consultation process at Threshold. Not only that, but learning some of the programs, the methodology, skills, and purpose of Threshold as well. The impact of the program has certainly opened my eyes to the field of architectural acoustics, and how much work has to go into a project for the best possible outcome. In essence, I found the experience to be one of the most impactful I had in my life.

On the development of virtual reality tools to aid in the design interior soundscapes

Can simulations of interiors spaces (visual and acoustic) be used to improve designs of spaces within buildings? The first step in the simulation of the sounds in a space is to characterize typical sound sources and their locations within the space. The next step is to characterize the paths from the sources to the user, based on geometry and materials used. Combining the contributions from all sources, is it possible to create sounds that are similar to sounds in the real environment? How close do simulated and measured sounds need to be to evoke similar emotional responses from users? The same questions arise for the visual experience and for interactions between the visual and acoustic experiences. Are there metrics that can be used to guide improvements in the virtual environment to match the real experience in the built environments? To start to answer these questions, a sound simulation program using an image source modeling approach was developed for spaces in an existing building. The impulse responses from the image source model and the measured impulse responses are compared, as are simulated and measured sounds. Room acoustics and sound quality metrics for the virtual and real sounds are also compared.

Airborne Acoustic Transmission and Terrain Topography at SAINTGITS Amphitheatre: An Analysis of Outdoor Auditory Perception and Comparison of Contour Plots

The arrangement of natural and physical features on the earth’s surface are a few among the countless items that govern the airborne acoustic transmission at boundary layers. In particular, if the acoustic waves are attributes of live concerts at open-air theatres, without losing the sheen and quality, the audience should certainly receive the unbroken depth of the performance. Hence, at all times, it is advisable to analyse the auditory receptiveness, particularly in all intended recreational spaces. The current pandemic circumstances and the mandated COVID-19 prevention protocols encourage gatherings in naturally ventilated outdoor regions than confined indoors. This work predicts and quantifies the acoustic experience at the naturally carved amphitheatre at SAINTGITS, an autonomous institution at the down South-West of the Indian Subcontinent. The entire recreational space at SAINTGITS AMPHI was separately modelled as a Base case and Advanced case, and were analysed using the acoustic modelling module of EASE Focus, a renowned simulation freeware, which is in strict adherence with the International standards. The variation in loudness received at the nearest and farthest ends of the amphitheatre was between 67 to 80 dB. Though the Zero frequency SPL (Z-weighting) exhibited the loudness in the range of 81 to 85 dB and could maintain a safer auditory level for any human ear, it was confined to a hemispherical region near the sound source. A vertical beam angle of −4.0° was found to be effective throughout. The procedures and analyses will certainly help the future organizers and stakeholders to effectively plan the resources to reap rich acoustic experience at terrain-centric locales. The surface topography and contours were plotted with another set of freeware, the CADMAPPER and the QUIKGRID, to compare terrain gradient with the known data. Furthermore, this interdisciplinary research exhibits the extensive simulation capability of both EASE Focus and QUIKGRID and demonstrates the modelling versatility and deliverable potential of these freeware to benefit the budding architects and researchers.

Read My Lips: Onscreen Visual Acoustics in Alfred Hitchcock’s Early Movies

This essay will cover some of Alfred Hitchcock’s early silent movies up to and including Blackmail (1929), of which he filmed both a silent and a sound version simultaneously. Hitchcock’s success with sound was directly linked to his training in silent technique. Silent movies actually allowed him to explore how they were capable of sound. This essay will consider how silent movies were able to induce an acoustic experience without the aid of extra-diegetic practices that added live – and sometimes gramophonic – soundtrack to films. What I am interested in is the aural effect of the visual experience of the screen alone. In the early days of cinema, the frame was silently read for all kind of sounds heard in the head of the spectator.

Acoustic wave focusing by 2.5D graded index lens

Three dimensional sound convergence in air underpins applications ranging from localized acoustic experiences to levitation. Most current solutions, however, are challenging to scale-up: they either require complex electronics or intricate geometries. In this paper, we propose a solution based on sonic crystals: an extruded 2D hexagonal lattice array of rigid cylinders with gradient diameters, capable of focusing in 3D emission of a standard loudspeaker at audio frequencies, which we call a 2.5D lens. First, we use finite-element simulations to describe the underpinning theory in terms of the band structure and equifrequency contours. We then describe how we manufactured two lenses, one of which has a focal length smaller than the wavelength, and compare pressure with simulations. Our measurements not only show good agreement with simulations but also highlight how the efficiency of such lenses strongly depends on how the sound is delivered to them.

Threshold and the consultation process

Here I had the opportunity to take part in the Acoustical Society of America’s (ASA) Summer Undergraduate Research or Internship Experience in Acoustics (SURIEA) Program. The program was designed for underrepresented minority groups in order to introduce them to the field of acoustics. After a two-week crash course I was able to experience what it was like working in an architectural acoustic consultation firm, and learn the extensive consultation process at Threshold. Not only that, but learning some of the programs, the methodology, skills, and purpose of Threshold as well. The impact of the program has certainly opened my eyes to the field of architectural acoustics, and how much work has to go into a project for the best possible outcome. In essence, I found the experience to be one of the most impact I had in my life.

The Roaring Streets: Dickensian London in the Pages of Virginia Woolf

Virginia Woolf was a keen preserver of some Victorian values, and among these the art of Charles Dickens, with his representation of London, its voices, sounds, music and noises. Dickens’s Little Dorrit and its closing sentence opens up my critical track by suggesting that Woolf’s reconstruction of the past must give to Victorian sounds a role that is neither ancillary nor merely impressionistic. This article focuses on Woolf’s portrayal of Victorian urban life in her fiction, especially in The Years (1937), where London sounds are everywhere present and deployed to create the polyphony—an exciting cacophony in modernist terms—of the great city. In Woolf’s fiction sounds are meant to convey symbolic meanings, to bring myth to the foreground, while also adding to the realism of the text. Sounds function like the many voices of an organ—the baroque instrument par excellence—suggesting at once order and chaos, norm and transgression: they frame representation and yet also break the frame by directly affecting the reader. This effect of discordia concors as acoustic experience is implemented within the verbal context, emphasizing the dialogic relationship between the source of sound, its reception, and the performative function sounds obtain within the texture of The Years.

Assessing room acoustic listening expertise.

Musicians and music professionals are often considered to be expert listeners for listening tests on room acoustics. However, these tests often target acoustic parameters other than those typically relevant in music such as pitch, rhythm, amplitude, or timbre. To assess the expertise in perceiving and understanding room acoustical phenomena, a listening test battery was constructed to measure the perceptual sensitivity and cognitive abilities in the identification of rooms with different reverberation times and different spectral envelopes. Performance in these tests was related to data from the Goldsmiths Musical Sophistication Index, self-reported previous experience in music recording and acoustics, and academic knowledge on acoustics. The data from 102 participants show that sensory and cognitive abilities are both correlated significantly with musical training, analytic listening skills, recording experience, and academic knowledge on acoustics, whereas general interest in and engagement with music do not show any significant correlations. The regression models, using only significantly correlated criteria of musicality and professional expertise, explain only small to moderate amounts (11%-28%) of the variance in the "room acoustic listening expertise" across the different tasks of the battery. Thus, the results suggest that the traditional criteria for selecting expert listeners in room acoustics are only weak predictors of their actual performances.

Smog Signals, Dog Sirens: Jia Zhangke, Lacan, and the Anthropocene

This study is a critique of two overlooked shorts of Jia Zhangke, a leading figure from the sixth generation of Chinese filmmakers: Smog Journeys (2015) and The Condition of Dogs (2001). Contemplating the imminent demise of human and animal lives represented, it argues that the looming ecological crises in the films stress biological finitude to such an extent that fear and pity disavow the truth about capitalist co-optation. To understand capitalism’s operation behind a catastrophic Anthropocene, I put the films into dialogues with Lacan’s “University Discourse” and “Hysteric’s Discourse”, formal structures that challenge and reshape the immediate identification of a narrative. With their attention to signifiers and affect, these formal structures enable us to understand how images and sounds focalize the viewers’ experience of fear and pity while unearthing the truth about the foreclosure of capitalist ideology. But instead of performing a strictly close-reading of each film, my critique elaborates more on the very psychoanalytic logic of Lacan’s two structures. My wish is that it allows us to see how complex visual and acoustic experience could be in shaping our identification beyond socio-cultural reflections and pure aesthetics. Article received: April 23, 2021; Article accepted: June 21, 2021; Published online: September 15, 2021; Original scholarly paper

Sonic Environments as Systems of Places: A Critical Reading of Husserl’s Thing and Space

Abstract This article offers a thorough and critical reading of Husserl’s Thing and Space. This reading is principally motivated by the effort to methodologically design a phenomenological–topological approach to the research of lived sonic environments. In this book, Husserl lays foundations of phenomenological topology by understanding perceptions as places and defining, consequently, the space as a system of places. The critical reading starts with pointing out the ambiguity of location in Thing and Space, which consists mainly in the insufficient implementation of the distinction between the location and the localization. Further investigations then reveal the roots of this ambiguity in both the preference of visual perception and the omission of subjective aspects of kinesthesia. The article critically examines Husserl’s notion of the appended localization that expresses the marginalization of (among others) acoustic experience. In conclusion, the article utilizes the critical findings to formulate the project of a place-based (phenomenological–topological), medium-centered, and multi-sensory approach to sonic environments.

Precolonial soundscapes of Swahili coastal towns in East Africa

ABSTRACT This paper aims to open the discussion on the characteristics of the acoustic landscapes in precolonial Swahili towns on the East African coast, where this theme to date remains unstudied. The paper focuses on assessing some aspects of the acoustic experience in the precolonial period of AD 1200–1600 respective to the towns and to coral-rag houses, which represent one type of building recorded on Swahili archaeological sites. Due to the limited preservation of buildings on the East African coast, and the fact that many of them have been deserted under the growing influence of Omani and European colonialism, both experimental and ethnoarchaeological studies could provide only limited information on any aspect of past sensory experience in these towns. Therefore, this paper defines some major characteristics of soundscapes in this region using analyses of the acoustic capacities and spatial dimensions of the Swahili built environment, while reflecting on selected themes that played a strong part in Swahili social environment, such as trade and Islam. The presented case study from sub-Saharan Africa aims to contribute to the global discussions on sensory experience in urban societies, where examples from coastal tropics are acutely needed.

Modulation of Theta Phase Synchrony during Syllable Processing as a Function of Interactive Acoustic Experience in Infancy.

Plasticity, a prominent characteristic of the infant brain, supports formation of cortical representations as infants begin to interact with and adapt to environmental sensory events. Enhanced acoustic processing efficiency along with improved allocation of attentional resources at 7 months and establishment of well-defined phonemic maps at 9 months have been shown to be facilitated by early interactive acoustic experience (IAE). In this study, using an oddball paradigm and measures of theta phase synchrony at source level, we examined short- and long-term effects of nonspeech IAE on syllable processing. Results demonstrated that beyond maturation alone, IAE increased the efficiency of syllabic representation and discrimination, an effect that endured well beyond the immediate training period. As compared with naive controls, the IAE-trained group at 7, 9, and 18 months showed less theta phase synchrony for the standard syllable and at 7 and 18 months for the deviant syllable. The decreased theta phase synchrony exhibited by the trained group suggests more mature, efficient, acoustic processing, and thus, better cortical representation and discrimination of syllabic content. Further, the IAE modulatory effect observed on theta phase synchrony in left auditory cortex at 7 and 9 months was differentially associated with receptive and expressive language scores at 12 and 18 months of age.

Orienting Auditory Attention through Vision: theImpactofMonaural Listening.

The understanding of linguistic messages can be made extremely complex by the simultaneous presence of interfering sounds, especially when they are also linguistic in nature. In two experiments, we tested if visual cues directing attention to spatial or temporal components of speech in noise can improve its identification. The hearing-in-noise task required identification of a five-digit sequence (target) embedded in a stream of time-reversed speech. Using a custom-built device located in front of the participant, we delivered visual cues to orient attention to the location of target sounds and/or their temporal window. In Exp. 1 ( n = 14), we validated this visual-to-auditory cueing method in normal-hearing listeners, tested under typical binaural listening conditions. In Exp. 2 ( n = 13), we assessed the efficacy of the same visual cues in normal-hearing listeners wearing a monaural ear plug, to study the effects of simulated monaural and conductive hearing loss on visual-to-auditory attention orienting. While Exp. 1 revealed a benefit of both spatial and temporal visual cues for hearing in noise, Exp. 2 showed that only the temporal visual cues remained effective during monaural listening. These findings indicate that when the acoustic experience is altered, visual-to-auditory attention orienting is more robust for temporal compared to spatial attributes of the auditory stimuli. These findings have implications for the relation between spatial and temporal attributes of sound objects, and when planning devices to orient audiovisual attention for subjects suffering from hearing loss.

Auralization of a car pass-by inside an urban canyon using measured impulse responses

Development of methodologies for the auralization of moving cars can be of great value for a virtual acoustic experience of urban areas. In this paper11Parts of this study were presented at the conference: Euronoise 2018, Crete, Greece a methodology for the auralization of car pass-by based on measured binaural impulse responses (BIRs) is presented. Measured BIRs for different locations in a street canyon were convolved with dry synthesized car signals in which cross-fade windows were applied in order to create a smooth transition between the source positions. Next, the convolved signals are summed in order to create the final car pass-by auralizations. A same/different listening test was carried out in order to investigate if increasing the angular spacing between the discrete source positions affects the perception of the auralizations. The experiments revealed that the auralizations with a larger angular increment (up to 16∘) are perceptually different to the reference auralizations (2∘ spacing), even in the case where the increment increased by only 2∘ compared to the reference. Compared to previous listening experiments of a car pass-by in the scenario without buildings it was shown that the discrimination performance of the subjects was significantly better compared to the test conditions where buildings are absent, where subjects found it very difficult to distinguish differences between auralizations of larger and smaller increment.

Sound and Soundscape in Restorative Natural Environments: A Narrative Literature Review.

Acoustic experiences of nature represent a growing area in restorative environments research and are explored in this narrative literature review. First, the work surveyed indicates that nature is broadly characterized by the sounds of birdsong, wind, and water, and these sounds can enhance positive perceptions of natural environments presented through visual means. Second, isolated from other sensory modalities these sounds are often, although not always, positively affectively appraised and perceived as restorative. Third, after stress and/or fatigue nature sounds and soundscapes can lead to subjectively and objectively improved mood and cognitive performance, as well as reductions in arousal, although some inconsistencies in findings are observed. Fourth, theoretical frameworks of restorative environments would benefit from inclusion of acoustic environmental properties such as sound intensity or frequency. Fifth, findings regarding positive, learned semantic associations with nature have arisen as a result of recent work on sounds and restoration. This represents another important area of potential theoretical development for broader restorative environments research.

Early acoustic experience alters genome-wide methylation in the auditory forebrain of songbird embryos

Early exposure to salient cues can critically shape the development of social behaviors. For example, both oscine birds and humans can hear and learn to recognize familiar sounds in ovo and in utero and recognize them following hatching and birth, respectively. Here we demonstrate that different chronic acoustic playbacks alter genome-wide methylation of the auditory forebrain in late-stage zebra finch (Taeniopygia guttata) embryos. Within the same subjects, immediate early gene activation in response to acute con- or heterospecific song exposure is negatively correlated with methylation extent in response to repeated daily prior exposure to the same type of stimuli. Specifically, we report less relative global methylation following playbacks of conspecific songs and more methylation following playbacks of distantly-related heterospecific songs. These findings offer a neuroepigenomic mechanism for the ontogenetic impacts of early acoustic experiences in songbirds.

On the acoustics of coupled volumes in the safavid architecture—Comparison of computer-modeled objective parameters of two historic buildings

One of the typical architectural prototypes in the Safavid era is the utilization of nested rooms for creating assembly spaces with spatial connectivity. Varied in geometry and size, each volume contributes differently to the acoustical environment. Shah Mosque prayer hall and Ali Qapu Palace music room are the two rooms that employ this organization system in their planning. Various simulations have been performed on 3D models of these architectural entities to study the mechanism of sound energy exchange and the impact of each volume on the perceived acoustic characteristics. The objective parameters were collected for both rooms and compared in various configurations to understand each cluster of space's impact on the overall acoustic experience. Furthermore, materials' properties, proportions, and architectural features are discussed as contributing factors to the sonic landscape. The result shows that the sound energy decay behaves differently mainly due to the two rooms' differences in scale and sound absorptive properties. The comparative analysis verifies some of the previous research on coupled volumes in which these two precedents exhibit a similar non-exponentialsound energy decay.

"Textual Prosody" Can Change Impressions of Reading in People With Normal Hearing and Hearing Loss.

Recently, dynamic text presentation, such as scrolling text, has been widely used. Texts are often presented at constant timing and speed in conventional dynamic text presentation. However, dynamic text presentation enables visually presented texts to indicate timing information, such as prosody, and the texts might influence the impression of reading. In this paper, we examined this possibility by focusing on the temporal features of digital text in which texts are represented sequentially and with varying speed, duration, and timing. We call this “textual prosody.” We used three types of textual prosody: “Recorded,” “Shuffled,” and “Constant.” Recorded prosody is the reproduction of a reader’s reading with pauses and varying speed that simulates talking. Shuffled prosody randomly shuffles the time course of speed and pauses in the recorded type. Constant prosody has a constant presentation speed and provides no timing information. Experiment 1 examined the effect of textual prosody on people with normal hearing. Participants read dynamic text with textual prosody silently and rated their impressions of texts. The results showed that readers with normal hearing preferred recorded textual prosody and constant prosody at the optimum speed (6 letters/second). Recorded prosody was also preferred at a low presentation speed. Experiment 2 examined the characteristics of textual prosody using an articulatory suppression paradigm. The results showed that some textual prosody was stored in the articulatory loop despite it being presented visually. In Experiment 3, we examined the effect of textual prosody with readers with hearing loss. The results demonstrated that readers with hearing loss had positive impressions at relatively low presentation speeds when the recorded prosody was presented. The results of this study indicate that the temporal structure is processed regardless of whether the input is visual or auditory. Moreover, these results suggest that textual prosody can enrich reading not only in people with normal hearing but also in those with hearing loss, regardless of acoustic experiences.