MyMedR

Displaying publications 21 - 40 of 72 in total

Abstract:

Sort:

Mating calls of selected Sarawak toads (Amphibia: Anura: Bufonidae)

Muhammad Fadzil Amram, Ramlah Zainudin, Hasnizam Abdul Wahid

Sains Malaysiana, 2018;47:1-7.

The sound produced by the anurans including toads can be a survival strategy for the selection of fittest males by their conspecific females and a form of effective prezygotic mechanism. Most of the published works on anuran sound production were on true frogs or ranids, yet little is known about sound characteristics of toads. Here we describe the properties of mating calls from six selected toad species from six study sites in Sarawak. Males' mating calls were recorded and analyzed using Sound Ruler Acoustic Analysis ver 0.9.6.0. Call characteristic were subsequently compared for toad species differentiation. The results showed that each species differ in call characteristics, with pulsating note, rate of note repetition and pitch being the most apparent characters. The highest number of pulse notes belongs to Duttaphrynus melanostictus while Ansonia spinulifer exhibited highest pitch and rate of note repetition. These species' differences in mating call characteristics provide an additional method for anuran species classification besides morphological and molecular DNA data. It is also a very useful guide during field survey as the sound is audible and identification can be made without the need of capturing the toads.

Matched MeSH terms: Sound
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 FEM Analysis of Sezawa Mode SAW Sensor for VOC Based on CMOS Compatible AlN/SiO₂/Si Multilayer Structure

Aslam MZ, Jeoti V, Karuppanan S, Malik AF, Iqbal A

Sensors (Basel), 2018 May 24;18(6).
PMID: 29882929 DOI: 10.3390/s18061687

A Finite Element Method (FEM) simulation study is conducted, aiming to scrutinize the sensitivity of Sezawa wave mode in a multilayer AlN/SiO₂/Si Surface Acoustic Wave (SAW) sensor to low concentrations of Volatile Organic Compounds (VOCs), that is, trichloromethane, trichloroethylene, carbon tetrachloride and tetrachloroethene. A Complimentary Metal-Oxide Semiconductor (CMOS) compatible AlN/SiO₂/Si based multilayer SAW resonator structure is taken into account for this purpose. In this study, first, the influence of AlN and SiO₂ layers’ thicknesses over phase velocities and electromechanical coupling coefficients (k²) of two SAW modes (i.e., Rayleigh and Sezawa) is analyzed and the optimal thicknesses of AlN and SiO₂ layers are opted for best propagation characteristics. Next, the study is further extended to analyze the mass loading effect on resonance frequencies of SAW modes by coating a thin Polyisobutylene (PIB) polymer film over the AlN surface. Finally, the sensitivity of the two SAW modes is examined for VOCs. This study concluded that the sensitivity of Sezawa wave mode for 1 ppm of selected volatile organic gases is twice that of the Rayleigh wave mode.

Matched MeSH terms: Sound
Fulltext Small scale imaging using ultrasonic tomography

Zakaria, Z., Fazalul Rahiman, M.H., Abdul Rahim, R., Megat Ali, M.S.A., Baharuddin, M.Y., Jahidin, A.H.

Journal of Nuclear and Related Technologies, 2009;2009(1):266-281.
MyJurnal

Ultrasound technology progressed through the 1960’s from simple A-mode and B-mode scans to today’s M-mode and Doppler two dimensional (2-D) and even three dimensional (3-D) systems. Modern ultrasound imaging has its roots in sonar technology after it was first described by Lord John Rayleigh over 100 years ago on the interaction of acoustic waves with media. Tomography technique was developed as a diagnostic tool in the medical area since the early of 1970’s. This research initially focused on how to retrieve a cross sectional images from living or non-living things. After a decade, the application of tomography systems span into the industrial area. However, the long exposure time of medical radiation-based method cannot tolerate the dynamic changes in industrial process two phase liquid/gas flow system.. An alternative system such as a process tomography system, can give information on the nature of the flow regime characteristic. The overall aim of this paper is to investigate the use of a small scale ultrasonic tomography method based on ultrasonic transmission mode tomography for online monitoring of liquid/gas flow in pipe/vessel system through ultrasonic transceivers application. This non-invasive technique applied sixteen transceivers as the sensing elements to cover the pipe/vessel cross section. The paper also details the transceivers selection criteria, hardware setup, the electronic measurement circuit and also the image reconstruction algorithm applied. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases.

Matched MeSH terms: Sound
Fulltext Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure, Context and Vocal Activity

Radford CA, Ghazali SM, Montgomery JC, Jeffs AG

PLoS One, 2016;11(2):e0149338.
PMID: 26890124 DOI: 10.1371/journal.pone.0149338

Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas.

Matched MeSH terms: Sound
Fulltext Effect of sea-bottom elasticity on the propagation of acoustic-gravity waves from impacting objects

Kadri U

Sci Rep, 2019 Jan 29;9(1):912.
PMID: 30696934 DOI: 10.1038/s41598-018-37626-z

Recent analysis of data, recorded on March 8th 2014 at the Comprehensive Nuclear-Test-Ban Treaty Organisation's hydroacoustic stations off Cape Leeuwin Western Australia, and at Diego Garcia, has led to the development of an inverse model for locating impacting objects on the sea surface. The model employs the phase velocity of acoustic-gravity waves that radiate during the impact, and only considers their propagation in the water layer. Here, we address a significant characteristic of acoustic-gravity waves: the ability to penetrate through the sea-bottom, which modifies the propagation speed and thus the arrival time of signals at the hydrophone station. Therefore, we revisit some signals that are associated with the missing Malaysian Aeroplane MH370, and illustrate the role of sea-bottom elasticity on determining impact locations.

Matched MeSH terms: Sound
Fulltext Noise characteristics of grass-trimming machine engines and their effect on operators

Mallick Z, Badruddin IA, Khaleed Hussain MT, Salman Ahmed NJ, Kanesan J

Noise Health, 2009 Apr-Jun;11(43):98-102.
PMID: 19414929 DOI: 10.4103/1463-1741.50694

Over the last few years, interaction of humans with noisy power-driven agricultural tools and its possible adverse after effects have been realized. Grass-trimmer engine is the primary source of noise and the use of motorized cutter, spinning at high speed, is the secondary source of noise to which operators are exposed. In the present study, investigation was carried out to determine the effect of two types of grass-trimming machine engines (SUM 328 SE and BG 328) noise on the operators in real working environment. It was found that BG-328 and SUM-328 SE produced high levels of noise, of the order of 100 and 105 dB(A), respectively, to which operators are exposed while working. It was also observed that situation aggravates when a number of operators simultaneously operate resulting in still higher levels of noise. Operators should be separated 15 meters from each other in order to avoid the combined level of noise exposure while working with these machines. It was found that SPL, of the grass-trimmer machine engines (BG-328 and SUM-328 SE), were higher than the limit of noise recommended by ISO, NIOSH, and OSHA for an 8-hour workday. Such a high level of noise exposure may cause physiological and psychological problems to the operators in long run.

Matched MeSH terms: Sound Spectrography
Fulltext Hawkmoths produce anti-bat ultrasound

Barber JR, Kawahara AY

Biol Lett, 2013 Aug 23;9(4):20130161.
PMID: 23825084 DOI: 10.1098/rsbl.2013.0161

Bats and moths have been engaged in aerial warfare for nearly 65 Myr. This arms race has produced a suite of counter-adaptations in moths, including bat-detecting ears. One set of defensive strategies involves the active production of sound; tiger moths' ultrasonic replies to bat attack have been shown to startle bats, warn the predators of bad taste and jam their biosonar. Here, we report that hawkmoths in the Choerocampina produce entirely ultrasonic sounds in response to tactile stimulation and the playback of biosonar attack sequences. Males do so by grating modified scraper scales on the outer surface of the genital valves against the inner margin of the last abdominal tergum. Preliminary data indicate that females also produce ultrasound to touch and playback of echolocation attack, but they do so with an entirely different mechanism. The anti-bat function of these sounds is unknown but might include startling, cross-family acoustic mimicry, warning of unprofitability or physical defence and/or jamming of echolocation. Hawkmoths present a novel and tractable system to study both the function and evolution of anti-bat defences.

Matched MeSH terms: Sound
Fulltext Game Theory-Based Cooperation for Underwater Acoustic Sensor Networks: Taxonomy, Review, Research Challenges and Directions

Muhammed D, Anisi MH, Zareei M, Vargas-Rosales C, Khan A

Sensors (Basel), 2018 Feb 01;18(2).
PMID: 29389874 DOI: 10.3390/s18020425

Exploring and monitoring the underwater world using underwater sensors is drawing a lot of attention these days. In this field cooperation between acoustic sensor nodes has been a critical problem due to the challenging features such as acoustic channel failure (sound signal), long propagation delay of acoustic signal, limited bandwidth and loss of connectivity. There are several proposed methods to improve cooperation between the nodes by incorporating information/game theory in the node's cooperation. However, there is a need to classify the existing works and demonstrate their performance in addressing the cooperation issue. In this paper, we have conducted a review to investigate various factors affecting cooperation in underwater acoustic sensor networks. We study various cooperation techniques used for underwater acoustic sensor networks from different perspectives, with a concentration on communication reliability, energy consumption, and security and present a taxonomy for underwater cooperation. Moreover, we further review how the game theory can be applied to make the nodes cooperate with each other. We further analyze different cooperative game methods, where their performance on different metrics is compared. Finally, open issues and future research direction in underwater acoustic sensor networks are highlighted.

Matched MeSH terms: Sound
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 Smart Walk Stick for Visually Impaired People: Design and Implementation

Saud, Safaa Najah, Manivannan, Dasarataan, Adzliza Binti Salmi, Lilysuriazna Raya

Journal of Management & Science, 2018;16(2):19-28.
MyJurnal

Nowadays, the scientific knowledge is developing frequently in numerous characteristics to be able to offer versatile and also safe and sound tendency for the users. At this time many of prevalent together with employed indicate by the visually impaired people are using the ivory stick, nonetheless it possesses constraints. With the recent technological innovation, it is easy to prolong the assistance acquire for people who have visual disability throughout their movability; this design endorses a cost-effective ultrasonic stick for visually encountered people today, to be able to achieve an exclusive self-reliance and even exempt from the additional assist. A portable convenient to use technology is designed which could recognize the obstructions in the way working with ultrasonic sensors in addition to vibrator. Ultrasonic sensors will be able to inspect three types of distinct heights. Vibrator is frequently used as a substitute gadget in the areas that surrounds with the minimal signal coverage also nosy environment. The buzzer and vibration motor are initialized while any kind of hindrance is identified. Global positioning system device presents the details about to the proceeding approach both work or even home, that has been supplied considering that control keys together with a contingency switch. Text message unit is utilized by the blind to send out SMS info to the saved phone numbers in the Arduino in the event of unexpected emergency.

Matched MeSH terms: Sound
Fulltext Time frequency analysis of peking gamelan

Sinin Hamdan, Iran Amri Musoddiq, Ahmad Fauzi Musib, Marini Sawawi

Pertanika Journal of Science & Technology, 2020;28(2):441-457.
MyJurnal

The tone of peking 1, 2, 3, 5, 6, 1’ was investigated using time-frequency analysis (TFA). The frequencies were measured using PicoScope oscilloscope, Melda analyzer in Cubase version 9 and Adobe version 3. Three different approaches for time-frequency analysis were used: Fourier spectra (using PicoScope), spectromorphology (using Melda analyzer) and spectrograms (using Adobe). Fourier spectra only identify intensity-frequency within entire signals, while spectromorphology identify the changes of intensity-frequency spectrum at fixed time and Adobe spectrograms identify the frequency with time. PicoScope reading produces the spectra of the fundamental and overtone frequencies in the entire sound. These overtones are non-harmonic since they are non-integral multiples of the fundamental. The fundamental frequencies of peking 1, 2, 3, 5, 6 were 1066Hz (C6), 1178Hz (D6), 1342Hz (E6), 1599Hz (G6) and 1793Hz (A6) respectively while peking 1’was 2123Hz (C7) i.e. one octave higher than peking 1. Melda analyzer reading proved that all peking sustained the initial fundamental frequency and overtone at t=0 until 2s. TFA from Adobe reading provides a description of the sound in the time-frequency plane. From TFA, peking 1, 2 and 6 exhibited a much gentler attack and more rapid decay than peking 3, 5 and 1’.

Matched MeSH terms: Sound
Fulltext Timbre spectrum of gamelan instruments from four Malay gamelan ensembles

Hamdan, Sinin, Ahmad Faudzi Musib, Musoddiq, Iran Amri, Marini Sawawi

Pertanika Journal of Science & Technology, 2020;28(2):459-476.
MyJurnal

Gamelan in general is categorized as a group of gongs. This traditional Malay gamelan ensemble is in a slendro scale i.e. five notes per octave. The rhythms, pitch, duration and loudness classify the various groups of gongs such as bonang, kenong, gender, peking and gambang. The cast bronze peking, kenong and bonang were chosen from a range of Malay gamelan ensemble from Universiti Malaysia Sarawak (UNIMAS), Universiti Putra Malaysia (UPM), Universiti Kebangsaan Malaysia (UKM) and Universiti Teknologi Mara (UiTM). The sounds were recorded by PicoScope Oscilloscope. The PicoScope software displays waveform and spectrum in time and frequency domain respectively. The peking lowest and highest frequencies from UiTM were 293 Hz and 1867 Hz, from UPM were 644 Hz and 1369 Hz, from UKM were 1064 Hz and 2131 Hz and from UNIMAS were 1072 Hz and 2105 Hz respectively. The kenong lowest and highest frequencies from UiTM were 259 Hz and 463 Hz, from UPM were 294 Hz and 543 Hz, from UKM were 300 Hz and 540 Hz and from UNIMAS were 293 Hz and 519 Hz respectively. The fundamental frequencies of bonang from UPM were higher than that of UKM, UiTM and UNIMAS. The harmonics were not successive but interrupted by another frequency. The harmonics of each bonang was similar except for gamelan from UKM.

Matched MeSH terms: Sound
The prioritization of visuo-spatial associations during mental imagery

Umar H, Mast FW, Cacchione T, Martarelli CS

Cogn Process, 2021 May;22(2):227-237.
PMID: 33404898 DOI: 10.1007/s10339-020-01010-5

While previous research has shown that during mental imagery participants look back to areas visited during encoding it is unclear what happens when information presented during encoding is incongruent. To investigate this research question, we presented 30 participants with incongruent audio-visual associations (e.g. the image of a car paired with the sound of a cat) and later asked them to create a congruent mental representation based on the auditory cue (e.g. to create a mental representation of a cat while hearing the sound of a cat). The results revealed that participants spent more time in the areas where they previously saw the object and that incongruent audio-visual information during encoding did not appear to interfere with the generation and maintenance of mental images. This finding suggests that eye movements can be flexibly employed during mental imagery depending on the demands of the task.

Matched MeSH terms: Sound
The effects of audio stimuli on auditory-evoked potential in normal hearing Malay adults

Ibrahim IA, Ting HN, Moghavvemi M

Int J Health Sci (Qassim), 2018 9 12;12(5):25-34.
PMID: 30202405

Objectives: The hearing process in the brain is very complicated and hard to solve. However, an understanding of the hearing process is an essential issue and needed in many rehabilitation or treatment applications. This study investigates and compares the effects of simple and complex sounds on latency and amplitude of various event-related potential (ERP) components to male ethnic Malay adults. Comparisons were made with previous studies.
Materials and Methods: Simple and complex sounds were used (pure tones and the naturally produced Malay consonant-vowels [CVs]) to evoke the cortical auditory-evoked potential (CAEP) signals. Moreover, this study analyzed the influence of related CAEP components that are distinct to the selected population and determined which of the ERP components among (CAEP) components is most affected by the two distinct stimuli. Moreover, the study used classification algorithms to discover the ability of the brain in distinguishing CAEP evoked by stimuli contrasts.
Results: The results showed some resemblance between our results and ERP waveforms outlined in previous studies conducted on native speakers of English. On the other hand, it was also observed that the P1 and N2 had a significant effect in amplitude due to different stimulus.
Conclusion: The results show high classification accuracy for the brain to distinguish auditory stimuli. Moreover, the results indicated some resemblance to previous studies conducted on native English speakers using similar tones and English CV stimuli. However, the amplitudes and latencies of the P1 were found to have a significant difference due to stimuli complexity.

Matched MeSH terms: Sound
Effect of constraint-induced music therapy in idiopathic sudden sensorineural hearing loss: A systematic review and meta-analysis

Vasiwala RA, Elhariri SY, Teng CL, Mohamad I

Noise Health, 2022;24(113):75-81.
PMID: 35900392 DOI: 10.4103/nah.nah_33_21

BACKGROUND: Idiopathic sudden sensorineural hearing loss (ISSNHL) is commonly encountered in audiologic and otolaryngologic practice. Constraint-induced music/sound therapy (CIMT) is characterized by the plugging of the normal ear (constraint) and the simultaneous, stimulation of the affected ear with music, which is based on a well-established neurorehabilitation approach. Corticosteroid therapy (CST) is the current mainstay of treatment. The prognosis for hearing recovery depends on many factors including the severity of hearing loss, age, and presence of vertigo.
OBJECTIVE: To analyze the effectiveness of CIMT with CST in ISSNHL.
METHODS: We performed a systematic search, using specific keywords relevant to our study, in PubMed, Cochrane Central Register of Controlled Trials, and additional sources of published trials till December 2020. We then screened all search results obtained according to our inclusion/exclusion criteria and performed a quality assessment on all studies using the Newcastle-Ottawa scale and using MedCalc, a meta-analysis was performed on suitable studies.
RESULTS: The recovery rates of three included nonrandomized studies were assessed at 1 to 3 months. A total of 229 (CST: 131, CST + CIMT: 98) patients were pooled for meta-analysis. The meta-analysis using the random-effect model found the relative risk of recovery rate within 3 months to be 1.213 (95% confidence interval 0.709-2.074), a result that is not statistically significant.
CONCLUSION: Although our analysis results do not demonstrate the noticeable effect of CIMT in ISSNHL, it can support be a gainful adjunct to CST for better hearing results than CST alone. Therefore, it needs further prospective randomized controlled multicenter trials with a large sample.

Matched MeSH terms: Sound
Fulltext I feel you: the design and evaluation of a domotic affect-sensitive spoken conversational agent

Lutfi SL, Fernández-Martínez F, Lorenzo-Trueba J, Barra-Chicote R, Montero JM

Sensors (Basel), 2013;13(8):10519-38.
PMID: 23945740 DOI: 10.3390/s130810519

We describe the work on infusion of emotion into a limited-task autonomous spoken conversational agent situated in the domestic environment, using a need-inspired task-independent emotion model (NEMO). In order to demonstrate the generation of affect through the use of the model, we describe the work of integrating it with a natural-language mixed-initiative HiFi-control spoken conversational agent (SCA). NEMO and the host system communicate externally, removing the need for the Dialog Manager to be modified, as is done in most existing dialog systems, in order to be adaptive. The first part of the paper concerns the integration between NEMO and the host agent. The second part summarizes the work on automatic affect prediction, namely, frustration and contentment, from dialog features, a non-conventional source, in the attempt of moving towards a more user-centric approach. The final part reports the evaluation results obtained from a user study, in which both versions of the agent (non-adaptive and emotionally-adaptive) were compared. The results provide substantial evidences with respect to the benefits of adding emotion in a spoken conversational agent, especially in mitigating users' frustrations and, ultimately, improving their satisfaction.

Matched MeSH terms: Sound Spectrography/methods*
Fulltext Vocalisations of the bigeye Pempheris adspersa: characteristics, source level and active space

Radford CA, Ghazali S, Jeffs AG, Montgomery JC

J Exp Biol, 2015 Mar;218(Pt 6):940-8.
PMID: 25617461 DOI: 10.1242/jeb.115295

Fish sounds are an important biological component of the underwater soundscape. Understanding species-specific sounds and their associated behaviour is critical for determining how animals use the biological component of the soundscape. Using both field and laboratory experiments, we describe the sound production of a nocturnal planktivore, Pempheris adspersa (New Zealand bigeye), and provide calculations for the potential effective distance of the sound for intraspecific communication. Bigeye vocalisations recorded in the field were confirmed as such by tank recordings. They can be described as popping sounds, with individual pops of short duration (7.9±0.3 ms) and a peak frequency of 405±12 Hz. Sound production varied during a 24 h period, with peak vocalisation activity occurring during the night, when the fish are most active. The source level of the bigeye vocalisation was 115.8±0.2 dB re. 1 µPa at 1 m, which is relatively quiet compared with other soniferous fish. Effective calling range, or active space, depended on both season and lunar phase, with a maximum calling distance of 31.6 m and a minimum of 0.6 m. The bigeyes' nocturnal behaviour, characteristics of their vocalisation, source level and the spatial scale of its active space reported in the current study demonstrate the potential for fish vocalisations to function effectively as contact calls for maintaining school cohesion in darkness.

Matched MeSH terms: Sound Spectrography
The electronic song "Scary Monsters and Nice Sprites" reduces host attack and mating success in the dengue vector Aedes aegypti

Dieng H, The CC, Satho T, Miake F, Wydiamala E, Kassim NFA, et al.

Acta Trop, 2019 Jun;194:93-99.
PMID: 30922800 DOI: 10.1016/j.actatropica.2019.03.027

Sound and its reception are crucial for reproduction, survival, and population maintenance of many animals. In insects, low-frequency vibrations facilitate sexual interactions, whereas noise disrupts the perception of signals from conspecifics and hosts. Despite evidence that mosquitoes respond to sound frequencies beyond fundamental ranges, including songs, and that males and females need to struggle to harmonize their flight tones, the behavioral impacts of music as control targets remain unexplored. In this study, we examined the effects of electronic music (Scary Monsters and Nice Sprites by Skrillex) on foraging, host attack, and sexual activities of the dengue vector Aedes aegypti. Adults were presented with two sound environments (music-off or music-on). Discrepancies in visitation, blood feeding, and copulation patterns were compared between environments with and without music. Ae. aegypti females maintained in the music-off environment initiated host visits earlier than those in the music-on environment. They visited the host significantly less often in the music-on than the music-off condition. Females exposed to music attacked hosts much later than their non-exposed peers. The occurrence of blood feeding activity was lower when music was being played. Adults exposed to music copulated far less often than their counterparts kept in an environment where there was no music. In addition to providing insight into the auditory sensitivity of Ae. aegypti to sound, our results indicated the vulnerability of its key vectorial capacity traits to electronic music. The observation that such music can delay host attack, reduce blood feeding, and disrupt mating provides new avenues for the development of music-based personal protective and control measures against Aedes-borne diseases.

Matched MeSH terms: Sound
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

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links