Sound Source Distance Research Articles

Effect of early versus late onset of partial visual loss on judgments of auditory distance.

It is important to know whether early-onset vision loss and late-onset vision loss are associated with differences in the estimation of distances of sound sources within the environment. People with vision loss rely heavily on auditory cues for path planning, safe navigation, avoiding collisions, and activities of daily living. Loss of vision can lead to substantial changes in auditory abilities. It is unclear whether differences in sound distance estimation exist in people with early-onset partial vision loss, late-onset partial vision loss, and normal vision. We investigated distance estimates for a range of sound sources and auditory environments in groups of participants with early- or late-onset partial visual loss and sighted controls. Fifty-two participants heard static sounds with virtual distances ranging from 1.2 to 13.8 m within a simulated room. The room simulated either anechoic (no echoes) or reverberant environments. Stimuli were speech, music, or noise. Single sounds were presented, and participants reported the estimated distance of the sound source. Each participant took part in 480 trials. Analysis of variance showed significant main effects of visual status (p<0.05) environment (reverberant vs. anechoic, p<0.05) and also of the stimulus (p<0.05). Significant differences (p<0.05) were shown in the estimation of distances of sound sources between early-onset visually impaired participants and sighted controls for closer distances for all conditions except the anechoic speech condition and at middle distances for all conditions except the reverberant speech and music conditions. Late-onset visually impaired participants and sighted controls showed similar performance (p>0.05). The findings suggest that early-onset partial vision loss results in significant changes in judged auditory distance in different environments, especially for close and middle distances. Late-onset partial visual loss has less of an impact on the ability to estimate the distance of sound sources. The findings are consistent with a theoretical framework, the perceptual restructuring hypothesis, which was recently proposed to account for the effects of vision loss on audition.

Optimum Piezo-Electric Based Energy Harvesting for Low-Power Wireless Networks with Power Complexity Considerations

Low-power wireless sensing-based networks suffer from many constraints and challenges. In this research work, efficient power source has been designed to provide the need of energy for the Wireless Sensor Networks (WSNs) and Wireless Body Area Networks (WBANs). The energy sources are the main challenge and constraint these wireless networks applications. This paper discusses recent researcher’s works which considered the energy constraints of the WSN and WMSN with their proposed security techniques. The main idea of this presented work is the energy harvesting through extracting the electrical energy from the audio/acoustic signal/energy, this utilized audio/acoustic source in this scenario is the disk jockey. To maximize the produced power from the proposed acoustic energy harvesting Piezo-based several parameters is studied. The parameters are considered in this research work are the method of Piezo-transducers connections, the distance of sound source, the sound intensity variation and the sound concentrating tube length. These tubes are mounted on slim diaphragm two maximize the energy harvesting. The piezoelectric transducer array scenario is designed using four piezoelectric transducers utilizing different connect ion methods, series, parallel and in hybrid. Several practically experiments are performed on the presented different scenarios to evaluate the proposed energy harvesting efficiency. These experiments reveal that the superiority of the proposed acoustic energy harvesting technique with low power complexity wireless networks and suitable with the different presented scenarios.

Subjective evaluation of source distance in dynamic 2.5D local sound field synthesis

Many loudspeakers are required to reproduce the immersive and physically-accurate sound field up to high frequency. Especially, at high frequency, a limited number of loudspeakers degrade the reproduction accuracy because of spatial Nyquist frequency. When use the same number of loudspeakers, reducing the extent of the reproduction region can improve the reproduction accuracy. However, by narrowing the reproduction region, the extent of movement for the listener is reduced. In our previous studies, we proposed the dynamic reproduction system of local sound field by moving the reproduction region to the listener's current position. Using a limited number of loudspeakers, the proposed system achieved the sound reproduction with high accuracy allowing the freedom of listener movement. In this study, we conduct the subjective evaluation of the dynamic 2.5D local sound field synthesis for sound source distance. Especially, we investigate the distance perception by allowing listeners to move around freely.

Development of Double Channel Transformer Voiceprint Detection System Based on MEMS Digital Silicon Microphone

Aiming for on-line monitoring of typical mechanical faults of transformer, a two-channel MEMS digital silicon wheat voice print detection system is developed, which consists of two channel MEMS digital silicon wheat array, the host of sound acquisition system and the upper computer software with the function of displaying real-time waveform and spectrum analysis. The device can operate reliably in complex environments by adjusting the array spacing, improving the power quality, and adjusting the network protocol. Further, different test environments were built to test the resolution performance of the equipment to the center frequency of the sound source at different distances and angles of the sound source. The results show that the system can realize the resolution of the center frequency of different sound source distance and Angle, and still has a good center frequency resolution performance in the case of environmental noise. At the same time, the system has strong stability, environmental adaptability, easy installation and non-contact detection characteristics, can be used for real-time detection and diagnosis of transformer faults.

Perceptual evaluation of an ambisonic auralization system of measured 3D acoustics

This paper presents a perceptual experiment aimed at assessing the spatial quality of acoustic environment rendering using a 4th order ambisonic auralization system. A novel test protocol is developed for this purpose, based on comparing the perceived spatial attributes of sound sources in both real (in-situ) and virtual listening conditions (loudspeaker-based ambisonic auralization of measured SRIRs). The perceptual evaluation is conducted using a specific reporting method combined with a virtual reality interface, enabling simultaneous assessment of perceived distance, angular position, and apparent width of sound sources. The test is conducted in three “office like” rooms, varying in reverberation properties and size. The results highlight differences in spatial perception between (a) real rooms and (b) their reproduction through the auralization system. Overall, localization performance is worse in auralized conditions than in real conditions, as evidenced by a clear increase in localization errors in azimuth and elevation, along with an increase in reported source width. This study also reveals that the spatial accuracy of the auralization depends on the rooms being auralized.

Residents’ Preferences to Multiple Sound Sources in Urban Park: Integrating Soundscape Measurements and Semantic Differences

Urban parks provide their residents with a space for activities and interactions, and soundscapes play an important role in influencing the residents’ sense of experience of the park environment, with the result that the preferences of residents regarding multiple sound sources can be used as the basis of improving the soundscape quality and optimizing the function of urban parks. Using Shanghai Century Park as the research area, this study focused on the residents’ preference to multiple sound sources based on registered residence differences, and comprehensively used the semantic differential method, importance-performance analysis model, and multinomial logit model to conduct quantitative research on urban park soundscapes and combined the measurement results of the soundscape with the residents’ perception and preference. The results showed that the artificial sounds in Century Park were noisy during the morning and evening peak, while the human sounds were noisy when residents gathered in the park. There was a close relationship between the favorability and subjective loudness of urban park soundscapes, and the residents’ perceptions of urban park soundscapes substantially differed in terms of loudness, tone, and sense of belonging, whereas the differences in the perception of timbre, coverage, and sound source distance were relatively small. Furthermore, it is necessary to enhance the role of natural sounds as well as control the main noise-producing sound sources so that various sounds in the park will not interfere with each other; the optimization of soundscapes should also focus on the residents’ different soundscape preferences due to their individual characteristics.

Integration of somatosensory and motor-related information in the auditory system.

An ability to integrate information provided by different sensory modalities is a fundamental feature of neurons in many brain areas. Because visual and auditory inputs often originate from the same external object, which may be located some distance away from the observer, the synthesis of these cues can improve localization accuracy and speed up behavioral responses. By contrast, multisensory interactions occurring close to the body typically involve a combination of tactile stimuli with other sensory modalities. Moreover, most activities involving active touch generate sound, indicating that stimuli in these modalities are frequently experienced together. In this review, we examine the basis for determining sound-source distance and the contribution of auditory inputs to the neural encoding of space around the body. We then consider the perceptual consequences of combining auditory and tactile inputs in humans and discuss recent evidence from animal studies demonstrating how cortical and subcortical areas work together to mediate communication between these senses. This research has shown that somatosensory inputs interface with and modulate sound processing at multiple levels of the auditory pathway, from the cochlear nucleus in the brainstem to the cortex. Circuits involving inputs from the primary somatosensory cortex to the auditory midbrain have been identified that mediate suppressive effects of whisker stimulation on auditory thalamocortical processing, providing a possible basis for prioritizing the processing of tactile cues from nearby objects. Close links also exist between audition and movement, and auditory responses are typically suppressed by locomotion and other actions. These movement-related signals are thought to cancel out self-generated sounds, but they may also affect auditory responses via the associated somatosensory stimulation or as a result of changes in brain state. Together, these studies highlight the importance of considering both multisensory context and movement-related activity in order to understand how the auditory cortex operates during natural behaviors, paving the way for future work to investigate auditory-somatosensory interactions in more ecological situations.

Initial Study of Converting Sound Energy into Electrical Energy

This study concerns on finding alternative source of energy by finding out the method of converting available and unused sound energy into electrical energy. The environmental issueincluding noise from the devices, factory etc has been increasing from year-to years. The purpose of this study includes to investigate the possibility of converting sound wave in a range between 70 dB to 80 dB into electrical energy by determining the effectiveness of the method to transform sound wave into electrical energy and study the percentage error between the theoretical and experimental output voltage produced. An electronic circuit-based experiment was conducted to fulfil the objectives of the study. Sound energy was converted into electrical energy by using microphonetransducer, then the brightness of bulb and the voltage reading was observed and tabulated. Theoretical and experimental voltage value were compared and being represented in percentage error value. The data shows that there is potential of converting sound into electricity through the suitable electrical circuit and the output voltage increase linearly with the sound pressure levels (SPL) of the sound sources. Further research should include the study of relationship between distance of sound sources and the transducer, and the output voltage produced

The estimation of distance and power of multiple sound sources by combining three-dimensional sound intensity and beamforming

The problem of identifying multiple sound sources occurs in various fields. This study proposes a method for multi-source localization and sound power estimation based on three-dimensional sound intensity (3DSI) measurement combined with high-precision beamforming. First, according to the propagation law of the point source in the free field and 3DSI measurement method, a mathematical model of the sound intensity vector, sound power, and source location in 3D space for multiple sources is derived. The 3DSI components can be measured by 3DSI probes. To reduce the computational cost required to solve the mathematical model, the angles of the sources are estimated via compressive sensing beamforming orthogonal matching pursuit for the method. Moreover, the sound intensity components and angles are used as inputs in the multiple sound source identification model, and the dimensions of the model are significantly reduced. The model was solved to obtain sound source distance and sound power. Two tetrahedral intensity probes and a 16-channel microphone array were used for experiments in a semi-anechoic chamber. The results demonstrate that the method can accurately identify the locations of multiple sound sources and determine the sound power. Considering three sound sources, the maximum angular error is 1.41°, while the maximum distance error is 0.08 m. This method can use a small number of probes to obtain the sound sources spatial position and sound source power, and it improve the resolution and calculation efficiency.

Optimization of number of microphones and microphone spacing using time delay based multilateration approach for explosive sound source localization

The use of microphone array for sound source localization has been a trending area of research in speech source recognition, battlefield acoustics, etc. For such applications, the localization accuracy is significantly influenced by the number of microphones and their arrangement on the ground surface. Thus, this paper proposes optimized microphone array geometries with the optimized number of microphones for positioning near and distant sound sources. Moreover, this paper also discusses the significance of the reference microphone selection on positioning accuracy. Here, the time-delay-based multilateration approach is used to formulate the governing nonlinear hyperbolic equations for sound source localization. The resulting equations are solved using the least square optimizer, the modified Levenberg Marquardt algorithm. The source results for several customized array structures are validated through simulation and experimental studies. Based on the results, this paper proposes that at least six microphones are required to identify a source position (<1800 m) with 97 % accuracy at lower noise thresholds (SNR: (6 to 20) dB) and 95 % accuracy at higher noise thresholds (SNR: -6 to 0 dB). Moreover, the paper suggests that microphone spacing should be a minimum of 0.34 times the source range for localization of distant sound sources to improve accuracy at higher and lower noise levels.

Azimuth-dependent model of binaural speech transmission index based on near-field head-related transfer functions

As well as the background noise and acoustic conditions of a given enclosed space, the binaural effect has a significant influence on the binaural speech transmission index (BSTI), especially for nearby sources. This effect can be quantitatively described by head-related transfer functions (HRTFs). As HRTFs are highly individual, the BSTIs from one person’s HRTF should differ from those of other people. However, this issue has rarely been studied. In the current work, we used the near-field HRTFs of 56 people to obtain the corresponding BSTIs, and analyzed the individual differences among them. The results show that the average standard deviation among the 56 individual BSTIs is almost within the just-noticeable-difference level of 0.03, and decreases with increasing sound source distance. We then acquired BSTIs from the KEMAR manikin and found that there were no significant differences with the median BSTIs across the 56 subjects. Thus, using the BSTIs of the KEMAR manikin, we developed regression BSTI models as a function of the azimuth based on seventh-order polynomial regression at different source distances.

Mechanical Fetal Simulator for Fetal Doppler Testing

The continuous use of fetal Doppler allows for discrepancies in values ​​that lead to misdiagnoses in patients. This study aims to determine the effect of sound source distance on the fetal simulator with the measurement point. The contribution of this research is that the mechanical fetal heart system has 4 distances so that later it can be analyzed whether there is an influence of the location of the sound source on the accuracy of measurements using a fetal simulator. To get the desired distance, a solenoid is used which ends with a pipe of 2 cm, 5 cm, 10 cm, and 50 cm respectively. The solenoid used in the fetal simulator functions as a producer of the fetal heart. There is a rotary switch that functions for solenoid selection, namely 2 cm, 5 cm, 10 cm and 50 cm solenoids. Data collection was carried out on each solenoid and by placing the Doppler probe perpendicular and tilted. On the solenoid with a distance of 50 cm all measurement results exceed the allowable tolerance limit. The results showed that the BPM value of the two Doppler brands did not have a significant difference in value. When measuring fetal Doppler, the largest error value was 2.67%. The results of this study can be used as a reference when conducting an examination

Concept understanding profile of high school students on doppler effect and sound intensity levels

The purpose of this study is to map the profile of high school students' conceptual understanding in physics subjects with the Doppler effect and sound intensity levels, and to show the causes of misconceptions in high school students from the results of the Certainty of Response Index (CRI) method applied. The research method is descriptive quantitative with data analysis techniques in the form of descriptive statistics. The data collection technique used is an ordinary multiple choice test instrument equipped with a confidence level scale using the model CRI (Certainty of Response Index). This confidence scale is used as data for understanding students' concepts in answering questions that are analyzed statistically. The research subjects were 66 high school students in class XI who were randomly selected and had received lessons on sound waves. The test results showed that there were misconceptions in each item with the largest percentage of 45.45% in item number 3 and the smallest 12.12% in item number 2. Other responses in the form of lucky guess and not knowing the concept were also found with varying percentages. The misconceptions encountered occurred in the use of signs for the speed of the observer and the speed of the source, the relationship between distance and number of sound sources at the level of sound intensity, and the relationship between sound magnitudes. The results of this concept understanding profile are expected to be information for teachers to be able to overcome students' misconceptions and arrange appropriate learning strategies during the learning process.

Sound Source Localization Using a Convolutional Neural Network and Regression Model.

In this research, a novel sound source localization model is introduced that integrates a convolutional neural network with a regression model (CNN-R) to estimate the sound source angle and distance based on the acoustic characteristics of the interaural phase difference (IPD). The IPD features of the sound signal are firstly extracted from time-frequency domain by short-time Fourier transform (STFT). Then, the IPD features map is fed to the CNN-R model as an image for sound source localization. The Pyroomacoustics platform and the multichannel impulse response database (MIRD) are used to generate both simulated and real room impulse response (RIR) datasets. The experimental results show that an average accuracy of 98.96% and 98.31% are achieved by the proposed CNN-R for angle and distance estimations in the simulation scenario at SNR = 30 dB and RT60 = 0.16 s, respectively. Moreover, in the real environment, the average accuracies of the angle and distance estimations are 99.85% and 99.38% at SNR = 30 dB and RT60 = 0.16 s, respectively. The performance obtained in both scenarios is superior to that of existing models, indicating the potential of the proposed CNN-R model for real-life applications.

Experimental evaluation on characteristics of a falling-film flow on the horizontal tube subject to ultrasonic field

The falling-film flow characteristics significantly influence the heat and mass transfer process in the horizontal tube absorber. This study experimentally investigates the effect of ultrasonic field on the flow mode transition and thickness distribution of the liquid film on the horizontal tube. The water-calcium chloride (CaCl2/water) was selected as the working fluid. The effects of the factors, such as the tube diameter, tube spacing, solution concentration, ultrasonic power, sound source distance and ultrasonic incidence angle, on the hydrodynamics of the liquid flow were analyzed. The results show that the mode transition Reynolds number increases with the increasing ultrasonic power, but reduces comparing to that without ultrasound. Moreover, in the column mode, the fluctuation range of the film thickness decreases with the increase of the ultrasound power; and the ultrasonic field help increase the average film thickness outside the tube and enhance the uniformity of liquid film.

Partial visual loss disrupts the relationship between judged room size and sound source distance

Visual spatial information plays an important role in calibrating auditory space. Blindness results in deficits in a number of auditory abilities, which have been explained in terms of the hypothesis that visual information is needed to calibrate audition. When judging the size of a novel room when only auditory cues are available, normally sighted participants may use the location of the farthest sound source to infer the nearest possible distance of the far wall. However, for people with partial visual loss (distinct from blindness in that some vision is present), such a strategy may not be reliable if vision is needed to calibrate auditory cues for distance. In the current study, participants were presented with sounds at different distances (ranging from 1.2 to 13.8 m) in a simulated reverberant (T60 = 700 ms) or anechoic room. Farthest distance judgments and room size judgments (volume and area) were obtained from blindfolded participants (18 normally sighted, 38 partially sighted) for speech, music, and noise stimuli. With sighted participants, the judged room volume and farthest sound source distance estimates were positively correlated (p < 0.05) for all conditions. Participants with visual losses showed no significant correlations for any of the conditions tested. A similar pattern of results was observed for the correlations between farthest distance and room floor area estimates. Results demonstrate that partial visual loss disrupts the relationship between judged room size and sound source distance that is shown by sighted participants.

Virtual sound source distance evaluation in acoustically and visually incongruent contexts

Visual and acoustic environment may influence the perception of auditory distance. In the context of Audio-only augmented reality (AAR), the coherence of the perceived virtual sound sources with the apparent room geometry and acoustics cannot always be guaranteed. The perceptual consequences of these incoherences are not well known. We conducted two online perceptual studies with a sound distance rendering model based on measured spatial room impulse responses (SRIR). A first study evaluated the perceptual performances of the model in incongruent visual contexts. The incongruent environment-related visual cues (spatial visual boundary and room volume) demonstrated a significant effect on the auditory distance perception (ADP) of virtual sound sources, through a calibration effect. A second study evaluated the impact of acoustical incongruence. Virtual sound sources distances were judged after the participant listened to distracting sound sources conveying distance cues relative to a different acoustical environment. When this distracting sound sources corresponded to a larger room than the one reproduced by the model, a higher compression effect was observed on the ADP of virtual sound sources. However, when the intensity cue conveyed by the distracting sound sources were coherent with the acoustical environment simulated by the model, their distracting effect were negligible.

Assessment of Sound Source Tracking Using Multiple Drones Equipped with Multiple Microphone Arrays.

Drone audition techniques are helpful for listening to target sound sources from the sky, which can be used for human searching tasks in disaster sites. Among many techniques required for drone audition, sound source tracking is an essential technique, and thus several tracking methods have been proposed. Authors have also proposed a sound source tracking method that utilizes multiple microphone arrays to obtain the likelihood distribution of the sound source locations. These methods have been demonstrated in benchmark experiments. However, the performance against various sound sources with different distances and signal-to-noise ratios (SNRs) has been less evaluated. Since drone audition often needs to listen to distant sound sources and the input acoustic signal generally has a low SNR due to drone noise, making a performance assessment against source distance and SNR is essential. Therefore, this paper presents a concrete evaluation of sound source tracking methods using numerical simulation, focusing on various source distances and SNRs. The simulated results captured how the tracking performance will change when the sound source distance and SNR change. The proposed approach based on location distribution estimation tended to be more robust against distance increase, while existing approaches based on directional estimation tended to be more robust against decreasing SNR.

Envisioning a Global Multi-Purpose Ocean Acoustic Network

Abstract Due to the efficient propagation of sound in water, sound in the deep ocean propagates such great distances that soundscapes are influenced not only by local conditions but also by distant sound sources. Ocean Sound is now an Essential Ocean Variable within the Global Ocean Observing System making passive acoustic monitoring routine. Active acoustic probing of the environment informs us about ocean topography, currents and temperature, and abundance and type of marine life vital to fisheries and biodiversity related interests.Efficient sound propagation is the foundation of a proposed multipurpose acoustic network. Judiciously placed low-frequency acoustic sources transmitting to globally distributed passive acoustic systems provide: (1) high temporal resolution measurements of large-scale ocean temperature/heat content variability using tomography; and (2) underwater geo-positioning (UW-GPS) and communication services enabling basin-scale underwater operation of floats, gliders, and AUVs. Every platform (fixed or moving) equipped with a hydrophone becomes a “GPS” receiver, while listening to the ocean soundscape. The combined active and passive acoustic technology will lead to multi-disciplinary discovery and improved understanding of ocean ecosystem health and biodiversity, climate variability and change, marine hazards, and maritime safety. The same system will improve the operation of gliders, floats and AUVs.

Multimodal fusion for indoor sound source localization

To identify the localization of indoor sound source, especially when attempted using only a single microphone, it is a challenging problem to machine learning. To address these issues, this paper presents a distinct novel solution based on fusing visual and acoustic models. Therefore, we propose two novel approaches. First, to estimate orientation of vocal object in a stable manner, we employ the visual approach as estimation model, where we develop a robust image feature representation method that adopts Fourier analysis to efficiently extract polar descriptors. Second the distance information is estimated by calculating the signal difference between transmit receive ends. To implement these, we use phoneme-level hidden Markov models (HMMs) extracted from clean speech sound, to estimate the acoustic transfer function (ATF), which can capture the speech signal as a network of phoneme HMMs. And using the separated frame sequences of the ATF, we can indicate the signal difference between two positions, which can be used to estimate the distance of sound source. Experimental results show that the proposed method can simultaneously extract the sound source parameters of direction and distance, and thus improves the verification task of sound source localization.