An influence of characteristics of amplitude fluctuation on detectability of alert sound of electric powered vehicles

2021 ◽  
Vol 263 (2) ◽  
pp. 4634-4640
Author(s):  
Nozomiko Yasui ◽  
Masanobu Miura ◽  
Tetsuya Shimamura

The motor sound on electric powered vehicle is quiet at low speeds. Thus, pedestrians have difficulty detecting the vehicles approaching them under urban noise. Although the vehicles were designed to play an alert sound to solve this problem, it has not been solved yet. Our previous studies found that characteristics of amplitude fluctuation, fluctuation frequency, non-periodic fluctuation and amplitude envelope, are effective to make them detect approaching vehicles. However, those studies were investigated under only a specific actual environment, weren't examined validity of detectability in those studies. Here, this paper investigates under another actual environment, examine the validity. Investigations were carried out by using synthesized complex sounds which were designed to have periodic and non-periodic amplitude fluctuations. Those complex sounds have characteristics of amplitude fluctuations in gasoline powered vehicle. Amplitude envelopes such as modulation wave in amplitude-modulated sound were set for deviations for time and amplitude, and amplitude-modulated complex sounds were synthesized using sine wave, sawtooth wave, and rectangle wave. Then, their effects on detectability by pedestrians were assessed in another actual environment. The results found that amplitude fluctuation enhances the ability with which people detect approaching electric powered vehicles in case of some complex sound.

1992 ◽  
Vol 336 (1278) ◽  
pp. 347-355 ◽  

To perceptually separate concurrent complex sounds, normally hearing listeners simultaneously combine information across a wide range of frequency components. Three psychoacoustical experiments are described which investigate different forms of this across-frequency processing. The first two experiments investigate the role of coherence of frequency modulation (FM) between widely separated frequency components of a complex sound.


2012 ◽  
Vol 542-543 ◽  
pp. 584-590
Author(s):  
Xian Qin Han ◽  
Xiang Lei Zhu

Signal generator is electronic equipment which can produce standard signals, and it often is used in industrial production electronic laboratories and the electronic equipment. Signal generator can achieve in a variety of methods, and the higher frequency and the more waveform is the better the signal generator condition. We can consider its implementation from the production and using areas. This paper will use function in the external circuit chip ICL8038 and electronic way to produce triangle wave, sine wave, rectangular wave,which are three basic rectangular waveforms, then the wave through ICM7216D, crystal, capacitors, switches and LED digital which are composed of the circuit to show the frequency and makes the sine wave produce a frequency modulation wave through FM circuit.


2017 ◽  
Vol 114 (5) ◽  
pp. E840-E848 ◽  
Author(s):  
Lei Feng ◽  
Xiaoqin Wang

Harmonicity is a fundamental element of music, speech, and animal vocalizations. How the auditory system extracts harmonic structures embedded in complex sounds and uses them to form a coherent unitary entity is not fully understood. Despite the prevalence of sounds rich in harmonic structures in our everyday hearing environment, it has remained largely unknown what neural mechanisms are used by the primate auditory cortex to extract these biologically important acoustic structures. In this study, we discovered a unique class of harmonic template neurons in the core region of auditory cortex of a highly vocal New World primate, the common marmoset (Callithrix jacchus), across the entire hearing frequency range. Marmosets have a rich vocal repertoire and a similar hearing range to that of humans. Responses of these neurons show nonlinear facilitation to harmonic complex sounds over inharmonic sounds, selectivity for particular harmonic structures beyond two-tone combinations, and sensitivity to harmonic number and spectral regularity. Our findings suggest that the harmonic template neurons in auditory cortex may play an important role in processing sounds with harmonic structures, such as animal vocalizations, human speech, and music.


2012 ◽  
Vol 614-615 ◽  
pp. 887-890 ◽  
Author(s):  
Lin Suo Zeng ◽  
Hong Yu Liu

The inverter part is an important link of the voltage source STATCOM, and a key problem of inverter is how to generate PWM switch signals according to given parameter. The part of SPWM inverter in STATCOM was simulated in Matlab. The result shows that the inverter bridge was controlled by the three-phase pulse width modulation wave produced by the SPWM and the three-phase sine wave at the side of the inverter bridge is outputted. This method is suitable for studying of the STATCOM system.


2011 ◽  
Vol 11 (10) ◽  
pp. 2699-2704 ◽  
Author(s):  
S. Ray ◽  
S. K. Chakrabarti ◽  
S. K. Mondal ◽  
S. Sasmal

Abstract. We present the results of an analysis of year-long (2007) monitoring of night time data of the VLF signal amplitude from the Indian Navy station VTX at 18.2 kHz, received by the Indian Centre for Space Physics, Kolkata. We analyzed this data to find out the correlation, if any, between night time amplitude fluctuation and seismic events. We found, analyzing individual cases (with magnitudes >5) as well as statistical analysis (of all the events with effective magnitudes greater than 3.5), that night time fluctuation of the signal amplitude has the highest probability to be beyond the 2σ level about three days prior to seismic events. Thus, the night time fluctuation could be considered as a precursor to enhanced seismic activities.


2014 ◽  
Vol 556-562 ◽  
pp. 464-467
Author(s):  
Qi Lei Sun ◽  
Lu Dan Shi ◽  
Ze Rui Liu

Based on the SSRT, by simulating different forms of applied loads, the paper conducts the research on the influence and mechanism of action from different waveforms upon the stress corrosion of pipeline steel. Results show that under the given F - SSRT testing condition, and when the fluctuation frequency and fluctuation amplitude are same, the sensitivity of the stress corrosion produced upon X70 pipeline steel is the weakest under the F-SSRT testing condition of superimposed square wave, and is the strongest under the F-SSRT testing condition of superimposed sine wave, which shows that the sensitivity degree of stress corrosion of materials under the F-SSRT with different load waveforms is obviously different.


1992 ◽  
Vol 336 (1278) ◽  
pp. 423-428 ◽  

In research on the neural mechanisms for the processing of biologically important sounds such as species-specific sounds and sounds produced by prey and predators, it is necessary to study responses of central auditory neurons to biologically im portant sounds, information-bearing elements (IBES) in them, and tone bursts. The tone bursts or constant-frequency (CF) components can be an IBE in many species of animals. Information-bearing parameters characterizing these sounds must be systematically varied, and tuning of neurons to individual parameters must be studied. The measurement of a tuning curve must be performed not only for excitatory responses, but also for inhibitory and facilitative responses, if any. The selectivity of a neuron to a particular type of sound must be tested for whether it is level-tolerant. Responses to complex sounds can probably be explained on the basis of those to IBES and tone bursts, so that the use of the tone bursts, even though they are not IBES, is as essential as that of the biologically important sounds.


1998 ◽  
Vol 08 (06) ◽  
pp. 1183-1197 ◽  
Author(s):  
Yoshisuke Ueda ◽  
Yoshinori Ueda ◽  
H. Bruce Stewart ◽  
Ralph H. Abraham

A model of a simple electric power supply network involving two generators connected by a transmission network to a bus is studied by numerical simulation. In this model, the bus is supposed to maintain a voltage of fixed amplitude, but with a small periodic fluctuation in the phase angle. In such a case, traditional analysis using direct methods is not applicable. The frequency of the periodic fluctuation is varied over a range of values near a nonlinear resonance of the two-generator network. When the bus fluctuation frequency is away from resonance, the system has several attractors; one is a small-amplitude periodic oscillation corresponding to synchronized, quasi-normal operation (slightly swinging), while others are large amplitude periodic oscillations which, if realized, would correspond to one or both generators operating in a desynchronized steady state. When the bus fluctuation frequency approaches resonance, a new periodic attractor with large amplitude oscillations appears. Although it does correspond to a synchronized steady state, this attractor has a disastrously large amplitude of oscillation, and represents an unacceptable condition for the network. Basin portraits show that this resonant attractor erodes large, complicated regions of the basin of the safe operating condition. Under conditions of small periodic fluctuation in bus voltage, this basin erosion would not be detected by traditional analysis using direct methods. Further understanding of such complicated basin structures will be essential to correctly predict the stability of electric power supply systems.


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