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Fulltext Updated parameters and expanded simulation options for a model of the auditory periphery

Zilany MS, Bruce IC, Carney LH

J Acoust Soc Am, 2014 Jan;135(1):283-6.
PMID: 24437768 DOI: 10.1121/1.4837815

A phenomenological model of the auditory periphery in cats was previously developed by Zilany and colleagues [J. Acoust. Soc. Am. 126, 2390-2412 (2009)] to examine the detailed transformation of acoustic signals into the auditory-nerve representation. In this paper, a few issues arising from the responses of the previous version have been addressed. The parameters of the synapse model have been readjusted to better simulate reported physiological discharge rates at saturation for higher characteristic frequencies [Liberman, J. Acoust. Soc. Am. 63, 442-455 (1978)]. This modification also corrects the responses of higher-characteristic frequency (CF) model fibers to low-frequency tones that were erroneously much higher than the responses of low-CF model fibers in the previous version. In addition, an analytical method has been implemented to compute the mean discharge rate and variance from the model's synapse output that takes into account the effects of absolute refractoriness.

Matched MeSH terms: Sound Spectrography
Emotional speech acoustic model for Malay: iterative versus isolated unit training

Mustafa MB, Ainon RN

J Acoust Soc Am, 2013 Oct;134(4):3057-66.
PMID: 24116440 DOI: 10.1121/1.4818741

The ability of speech synthesis system to synthesize emotional speech enhances the user's experience when using this kind of system and its related applications. However, the development of an emotional speech synthesis system is a daunting task in view of the complexity of human emotional speech. The more recent state-of-the-art speech synthesis systems, such as the one based on hidden Markov models, can synthesize emotional speech with acceptable naturalness with the use of a good emotional speech acoustic model. However, building an emotional speech acoustic model requires adequate resources including segment-phonetic labels of emotional speech, which is a problem for many under-resourced languages, including Malay. This research shows how it is possible to build an emotional speech acoustic model for Malay with minimal resources. To achieve this objective, two forms of initialization methods were considered: iterative training using the deterministic annealing expectation maximization algorithm and the isolated unit training. The seed model for the automatic segmentation is a neutral speech acoustic model, which was transformed to target emotion using two transformation techniques: model adaptation and context-dependent boundary refinement. Two forms of evaluation have been performed: an objective evaluation measuring the prosody error and a listening evaluation to measure the naturalness of the synthesized emotional speech.

Matched MeSH terms: Sound Spectrography
Whistle description of Irrawaddy dolphins (Orcaella brevirostris) in Bay of Brunei, Sarawak, Malaysia

Muhamad HM, Xu X, Zhang X, Jaaman SA, Muda AM

J Acoust Soc Am, 2018 05;143(5):2708.
PMID: 29857727 DOI: 10.1121/1.5036926

Studies of Irrawaddy dolphins' acoustics assist in understanding the behaviour of the species and thereby conservation of this species. Whistle signals emitted by Irrawaddy dolphin within the Bay of Brunei in Malaysian waters were characterized. A total of 199 whistles were analysed from seven sightings between January and April 2016. Six types of whistles contours named constant, upsweep, downsweep, concave, convex, and sine were detected when the dolphins engaged in traveling, foraging, and socializing activities. The whistle durations ranged between 0.06 and 3.86 s. The minimum frequency recorded was 443 Hz [Mean = 6000 Hz, standard deviation (SD) = 2320 Hz] and the maximum frequency recorded was 16 071 Hz (Mean = 7139 Hz, SD = 2522 Hz). The mean frequency range (F.R.) for the whistles was 1148 Hz (Minimum F.R. = 0 Hz, Maximum F.R. = 4446 Hz; SD = 876 Hz). Whistles in the Bay of Brunei were compared with population recorded from the waters of Matang and Kalimantan. The comparisons showed differences in whistle duration, minimum frequency, start frequency, and number of inflection point. Variation in whistle occurrence and frequency may be associated with surface behaviour, ambient noise, and recording limitation. This will be an important element when planning a monitoring program.

Matched MeSH terms: Sound Spectrography/methods
Whistles emitted by Indo-Pacific humpback dolphins (Sousa chinensis) in Zhanjiang waters, China

Dong L, Caruso F, Lin M, Liu M, Gong Z, Dong J, et al.

J Acoust Soc Am, 2019 06;145(6):3289.
PMID: 31255103 DOI: 10.1121/1.5110304

Whistles emitted by Indo-Pacific humpback dolphins in Zhanjiang waters, China, were collected by using autonomous acoustic recorders. A total of 529 whistles with clear contours and signal-to-noise ratio higher than 10 dB were extracted for analysis. The fundamental frequencies and durations of analyzed whistles were in ranges of 1785-21 675 Hz and 30-1973 ms, respectively. Six tonal types were identified: constant, downsweep, upsweep, concave, convex, and sine whistles. Constant type was the most dominant tonal type, accounting for 32.51% of all whistles, followed by sine type, accounting for 19.66% of all whistles. This paper examined 17 whistle parameters, which showed significant differences among the six tonal types. Whistles without inflections, gaps, and stairs accounted for 62.6%, 80.6%, and 68.6% of all whistles, respectively. Significant intraspecific differences in all duration and frequency parameters of dolphin whistles were found between this study and the study in Malaysia. Except for start frequency, maximum frequency and the number of harmonics, all whistle parameters showed significant differences between this study and the study conducted in Sanniang Bay, China. The intraspecific differences in vocalizations for this species may be related to macro-geographic and/or environmental variations among waters, suggesting a potential geographic isolation among populations of Indo-Pacific humpback dolphins.

Matched MeSH terms: Sound Spectrography/methods
Fulltext Post-Attentive Integration and Topographic Map Distribution During Audiovisual Processing in Dyslexia: A P300 Event-Related Component Analysis

Ali SA, Begum T, Reza MF, Fadzil NA, Mustafar F

Malays J Med Sci, 2020 Jul;27(4):130-138.
PMID: 32863752 DOI: 10.21315/mjms2020.27.4.12

Background: Research on audiovisual post-attentive integration has been carried out using a variety of experimental paradigms and experimental groups but not yet studied in dyslexia. We investigated post-attentive integration and topographic voltage distribution in children with dyslexia by analysing the P300 event-related potential (ERP) component.
Methods: We used a 128-child ERP net for the ERP experiment. Two types of stimuli were presented as either congruent or incongruent stimuli. Congruent stimuli included a matching auditory sound with an animal image, whereas incongruent stimuli included unmatched animal sounds. A total of 24 age-matched children were recruited in the control (n = 12) and dyslexia (n = 12) groups. Children pressed button '1' or '2' when presented with congruent or incongruent stimuli, respectively. The P300 amplitudes and latencies with topographic voltage distribution were analysed for both groups.
Results: The dyslexia group evoked significantly higher P300 amplitudes at the T4 area than the control group. No significant differences were found in cases of P300 latency. Moreover, the dyslexia group demonstrated a higher intensity of P300 voltage distribution in the right parietal and left occipital areas than the control group.
Conclusion: Post-attentive integration for children with dyslexia is higher and that this integration process implicated the parietal and occipital areas.

Matched MeSH terms: Sound
Fulltext Validity and Reliability Aspects of a Newly Developed Questionnaire for Auditory Localization

Zakaria MN

J Int Adv Otol, 2019 Apr;15(1):182-183.
PMID: 30924773 DOI: 10.5152/iao.2019.5959
Matched MeSH terms: Sound Localization/physiology*
Fulltext Acoustic emission monitoring of multicell reinforced concrete box girders subjected to torsion

Bagherifaez M, Behnia A, Majeed AA, Hwa Kian C

ScientificWorldJournal, 2014;2014:567619.
PMID: 25180203 DOI: 10.1155/2014/567619

Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothed b-value analysis.

Matched MeSH terms: Sound*
Fulltext Condition assessment of PC tendon duct filling by elastic wave velocity mapping

Liu KF, Chai HK, Mehrabi N, Yoshikazu K, Shiotani T

ScientificWorldJournal, 2014;2014:194295.
PMID: 24737961 DOI: 10.1155/2014/194295

Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT) technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC) elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.

Matched MeSH terms: Sound
Fulltext Characterisation of structure-borne sound source using reception plate method

Putra A, Saari NF, Bakri H, Ramlan R, Dan RM

ScientificWorldJournal, 2013;2013:742853.
PMID: 24324380 DOI: 10.1155/2013/742853

A laboratory-based experiment procedure of reception plate method for structure-borne sound source characterisation is reported in this paper. The method uses the assumption that the input power from the source installed on the plate is equal to the power dissipated by the plate. In this experiment, rectangular plates having high and low mobility relative to that of the source were used as the reception plates and a small electric fan motor was acting as the structure-borne source. The data representing the source characteristics, namely, the free velocity and the source mobility, were obtained and compared with those from direct measurement. Assumptions and constraints employing this method are discussed.

Matched MeSH terms: Sound Spectrography/methods*
Fulltext THE PERFORMANCE ANALYSIS OF OPTICAL WAVE PROPAGATION FOR UNDERWATER WIRELESS COMMUNICATION

MUHAMMAD SAFIY SABRIL, MUHAMMAD SAFIY SABRIL, FAEZAH JASMAN, NURUL ADILAH ABDUL LATIFF, SEVIA MAHDALIZA IDRUS, WAN HAFIZA WAN HASSAN

UMT Journal of Undergraduate Research, 2020;2(3):73-82.
MyJurnal

Underwater wireless communications refer to transmitting data in an unguided water environment by wireless carriers including acoustic, radio frequency (RF), and optical waves. Relative to acoustic and RF, the optical wave is more promising to offer higher bandwidth at a lower energy consumption rate. However, an optical wave has its challenges such as attenuation due to absorption, scattering and turbulence effects. Therefore, this work attempts to investigate the performance of lightwave propagation for underwater optical wireless communication (UOWC) using simulation and experimental approaches. First, the performance of optical waves was analyzed using MATLAB by simulating the light attenuation model which based on depth-dependent chlorophyll concentration. A depth profile that related to the surface chlorophyll levels for the range 0-4 mg/m3 was used to represent the open ocean. The simulation showed that the attenuation of light less affected for operating wavelength range of 450 – 550 nm. Further, an experimental set-up was developed which consists of a transmitter, receiver, and aquarium to emulate the UOWC channel. Three types of water including clear, sea and cloudy were tested to analyze their interaction with the light emitted by a light-emitting diode (LED) and a laser diode. The emitted light detected by the light sensor and the strength of an audio signal transmitted through the UOWC were measured using a light meter and sound meter respectively. The measured power was plotted against distance and the attenuation constant c was deduced through curve fitting method. The analysis showed irrespective of the light sources, UOWC in cloudy water suffered the highest attenuation relative to still clear and seawater. The received power emitted by laser was at least 41% higher than the LED. This study contributes to identify the potential and limitations of different operating schemes to optimize UOWC performance.

Matched MeSH terms: Sound
Fulltext Influence of MHz-order acoustic waves on bacterial suspensions

Chew NSL, Ooi CW, Yeo LY, Tan MK

Ultrasonics, 2024 Mar;138:107234.
PMID: 38171227 DOI: 10.1016/j.ultras.2023.107234

The development of alternative techniques to efficiently inactivate bacterial suspensions is crucial to prevent transmission of waterborne illness, particularly when commonly used techniques such as heating, filtration, chlorination, or ultraviolet treatment are not practical or feasible. We examine the effect of MHz-order acoustic wave irradiation in the form of surface acoustic waves (SAWs) on Gram-positive (Escherichia coli) and Gram-negative (Brevibacillus borstelensis and Staphylococcus aureus) bacteria suspended in water droplets. A significant increase in the relative bacterial load reduction of colony-forming units (up to 74%) can be achieved by either increasing (1) the excitation power, or, (2) the acoustic treatment duration, which we attributed to the effect of the acoustic radiation force exerted on the bacteria. Consequently, by increasing the maximum pressure amplitude via a hybrid modulation scheme involving a combination of amplitude and pulse-width modulation, we observe that the bacterial inactivation efficiency can be further increased by approximately 14%. By combining this scalable acoustic-based bacterial inactivation platform with plasma-activated water, a 100% reduction in E. coli is observed in less than 10 mins, therefore demonstrating the potential of the synergistic effects of MHz-order acoustic irradiation and plasma-activated water as an efficient strategy for water decontamination.

Matched MeSH terms: Sound
Enhancing greywater treatment via MHz-Order surface acoustic waves

Chan JS, Poh PE, Ismadi MP, Yeo LY, Tan MK

Water Res, 2020 Feb 01;169:115187.
PMID: 31671294 DOI: 10.1016/j.watres.2019.115187

There is a pressing need for efficient biological treatment systems for the removal of organic compounds in greywater given the rapid increase in household wastewater produced as a consequence of rapid urbanisation. Moreover, proper treatment of greywater allows its reuse that can significantly reduce the demand for freshwater supplies. Herein, we demonstrate the possibility of enhancing the removal efficiency of solid contaminants from greywater using MHz-order surface acoustic waves (SAWs). A key distinction of the use of these high frequency surface acoustic waves, compared to previous work on its lower frequency (kHz order) bulk ultrasound counterpart for wastewater treatment, is the absence of cavitation, which can inflict considerable damage on bacteria, thus limiting the intensity and duration, and hence the efficiency enhancement, associated with the acoustic exposure. In particular, we show that up to fivefold improvement in the removal efficiency can be obtained, primarily due to the ability of the acoustic pressure field in homogenizing and reducing the size of bacterial clusters in the sample, therefore providing a larger surface area that promotes greater bacteria digestion. Alternatively, the SAW exposure allows the reduction in the treatment duration to achieve a given level of removal efficiency, thus facilitating higher treatment rates and hence processing throughput. Given the low-cost of the miniature chipscale platform, these promising results highlight its possibility for portable greywater treatment for domestic use or for large-scale industrial wastewater processing through massive parallelization.

Matched MeSH terms: Sound

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