Travelers’ exposure to vibrations and noise depending on the type of transport – the results of pilot research

For some time residents of big cities have been encouraged to change their means of transport, that is, to swap passenger cars for public transport vehicles. This is meant to help to reduce the problems associated with heavy traffic and air pollution. The authors of the article decided to check if such a change is also beneficial from the point of view of comfort and health of a person who uses public transport. For this purpose values of vibration acceleration and sound pressure level to which Cracow’s commuters are exposed to have been analyzed, depending on the type of vehicle they choose. In this respect measurements have been carried out for passenger cars, buses and trams. Two vehicle models of each type, significantly different from each other (old and new) have been selected for the tests. The measurements during a few trips in each type of vehicle on a predetermined route have been conducted. This article presents a comparison of measured values of vibroacoustic parameters in the time domain. It attempts to assess vibration and noise parameters, taking into account their impact on the health and comfort of the traveler.

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Experimental Study on the Performance of Constrained Damped Rail Vibration Reduction

Noise & Vibration Worldwide ◽

10.1260/0957-4565.42.10.9 ◽

2011 ◽

Vol 42 (10) ◽

pp. 9-14

Author(s):

L.Y. Liu ◽

J.Y. Li ◽

X.J. Yin

Keyword(s):

Experimental Study ◽

Time Domain ◽

Vibration Amplitude ◽

Impact Load ◽

Vibration Reduction ◽

Time Domain Analysis ◽

Experimental Basis ◽

Vibration Acceleration ◽

The Time Domain ◽

Vibration Performance

To study the vibration reduction performance of damped rail, we take the standard rail and labyrinth constrained damped rail as the study target. By testing the vibration performance of both standard rail and labyrinth constrained damped rail in an anechoic room, we use the time-domain analysis to study the vibration changes with time passing. The results showed that: the labyrinth constrained damped rail vibration can effectively reduce the vibration amplitude and duration. Under the radial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 5% −19%, time of vibration and attenuation greater than 94%; under the axial impact load, compared to the standard rail, vibration acceleration attenuation of the labyrinth constrained damped rail is 9% −21%, time of vibration and attenuation greater than 92%. The results have provided an experimental basis for the design of new constrained damped rail.

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Visual and acoustic performance of shading devices – real scale laboratory measurements

E3S Web of Conferences ◽

10.1051/e3sconf/201911106072 ◽

2019 ◽

Vol 111 ◽

pp. 06072 ◽

Cited By ~ 1

Author(s):

Tiberiu Catalina ◽

Alexandra Ene ◽

Andreea Biro

Keyword(s):

Sound Pressure Level ◽

Sound Pressure ◽

Pressure Level ◽

Point Of View ◽

Physical Parameters ◽

Main Role ◽

Reverberation Time ◽

Illuminance Level ◽

Shading Devices ◽

Enclosed Space

There are several physical parameters that are taken into consideration when determining the level of agreeability of an enclosed space. For instance, when choosing the louvers for a room there are a multitude of criteria that might be considered such as colour, material or the degree of opacity. However, these apparently small fixtures may have a significant impact also on other apparently unimportant factors like the sound pressure level and the reverberation time. This paper aims to present different types of devices used to control the way daylight enters a room, from both the illuminance level and the acoustical point of view. During the experimental campaign, five of the most common types of louvers were examined regarding their main role of blocking the light and moreover their influence on the reverberation time and sound pressure level in the analysed chamber.

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Reconstruction of the Force Applied to a Plate in the Time Domain From Sound Pressure Measurements

Journal of Vibration and Acoustics ◽

10.1115/1.4046176 ◽

2020 ◽

Vol 142 (3) ◽

Author(s):

Chuan-Xing Bi ◽

Long Hu ◽

Yong-Bin Zhang ◽

Xiao-Zheng Zhang

Keyword(s):

Time Domain ◽

Sound Pressure ◽

Microphone Array ◽

Near Field ◽

Impulse Response Function ◽

Time History ◽

Pressure Measurements ◽

Concentrated Force ◽

Vibration Responses ◽

The Time Domain

Abstract This paper provides a non-contact approach to reconstruct the distributed or concentrated force applied to a plate in the time domain. This approach is based on sound pressure measurements and is realized by coupling the techniques of real-time near-field acoustic holography (RT-NAH) and force reconstruction. A microphone array is used to measure the sound pressures in the near field of the plate. The measured sound pressures are taken as the inputs of the RT-NAH to reconstruct the vibration responses, including the normal acceleration, velocity, and displacement, on the surface of the plate. With the reconstructed vibration responses, the equation of motion governing the forced vibration can be further processed to reconstruct the force applied to the plate in the time domain. In the process of reconstructing the vibration responses, a displacement–pressure impulse response function is derived for the first time and is used in the RT-NAH. Results of numerical simulations as well as experiments demonstrate that the proposed approach can identify the location of the force accurately and reconstruct the time history of the force effectively, thereby helping to diagnose the mechanical cause of the radiated noise.

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Performance Analysis of Piezoelectric Actuators in Railway Wheel Squealing Noise Mitigation

Shock and Vibration ◽

10.1155/2019/1232350 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13

Author(s):

Seyed Rahim Marjani ◽

Davood Younesian

Keyword(s):

Sound Pressure ◽

Near Field ◽

Pressure Level ◽

Contact Forces ◽

Railway Track ◽

Noise Mitigation ◽

Method Performance ◽

The Time Domain ◽

Squeal Noise ◽

Railway Wheels

Application of a shunted piezoelectric system in reduction of the squeal noise level in railway wheels is studied. A wheel squeal model including the railway track, wheel, and nonlinear interaction contact forces is taken into account in the time domain. Consequent vibration of the wheel is calculated at incident of sharp curve passing. The sound pressure level (SPL) of the noise is then calculated by an analytical method. Performance of different shunt circuits including the R (resistance) and RL (resistance inductance) is evaluated in different frequency ranges. A new methodology is proposed to achieve multimode damping. According to results, the SPL of wheel squeal noise can effectively get reduced by the proposed method, up to 5 dB at near-field and 10 dB at far-field.

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A numerical code for underwater noise propagation

MATEC Web of Conferences ◽

10.1051/matecconf/201821005017 ◽

2018 ◽

Vol 210 ◽

pp. 05017

Author(s):

Antonio Faggio ◽

Massimo Viscardi ◽

Tommaso Coppola ◽

Enrico Rizzuto

Keyword(s):

Sound Pressure Level ◽

Sound Pressure ◽

Sea Water ◽

Pressure Level ◽

Point Of View ◽

Numerical Code ◽

International Treaties ◽

Underwater Noise ◽

Marine Fauna ◽

The Impact

A growing attention has been recently devoted to the impact of the underwater noise field generated by shipping activities on the marine fauna. While in international treaties and conventions this problem is now well treated, from a technical point of view the quantification of the impact of underwater noise emissions from the ship is not yet consolidated. The program created allows the user to identify the sound rays generated by source and, between these, to find the beam nearest a receiver calculating the Trasmission Loss (TL). The user enters as input data the source position, the Sound Pressure Level (SPL) of the source, the depth of the backdrop, sound velocity profile, thickness of the layers in which the water column is divided, salinity, temperature and pH of sea water and the frequency of emission of the source to characterize the propagation environment. Through the Ray Tracing Theory, a technique of optical geometry that is based on the calculation of the path made by light the rays are shown on the screen. Then the rays closest to the receiver are identified and the program calculates the sound loss, divided into Geometrical Loss (due to distance between the source and the receiver), Dissipation Loss (due to the characteristics of the propagation environment) and Reflection Loss (due to the surfaces that delimit the field).In output the program will show the propagation field of the Sound Pressure Level through which in the future it will be possible to identify the emission limits to protect the marine fauna.

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Contributions of Voice and Nonverbal Communication to Perceived Masculinity–Femininity for Cisgender and Transgender Communicators

Journal of Speech Language and Hearing Research ◽

10.1044/2019_jslhr-19-00387 ◽

2020 ◽

Vol 63 (4) ◽

pp. 931-947

Author(s):

Teresa L. D. Hardy ◽

Carol A. Boliek ◽

Daniel Aalto ◽

Justin Lewicke ◽

Kristopher Wells ◽

...

Keyword(s):

Fundamental Frequency ◽

Sound Pressure Level ◽

Sound Pressure ◽

Vocal Tract ◽

Presentation Mode ◽

Pressure Level ◽

Presentation Modes ◽

Audiovisual Stimuli ◽

Vocal Tract Resonance ◽

Point Light

Purpose The purpose of this study was twofold: (a) to identify a set of communication-based predictors (including both acoustic and gestural variables) of masculinity–femininity ratings and (b) to explore differences in ratings between audio and audiovisual presentation modes for transgender and cisgender communicators. Method The voices and gestures of a group of cisgender men and women ( n = 10 of each) and transgender women ( n = 20) communicators were recorded while they recounted the story of a cartoon using acoustic and motion capture recording systems. A total of 17 acoustic and gestural variables were measured from these recordings. A group of observers ( n = 20) rated each communicator's masculinity–femininity based on 30- to 45-s samples of the cartoon description presented in three modes: audio, visual, and audio visual. Visual and audiovisual stimuli contained point light displays standardized for size. Ratings were made using a direct magnitude estimation scale without modulus. Communication-based predictors of masculinity–femininity ratings were identified using multiple regression, and analysis of variance was used to determine the effect of presentation mode on perceptual ratings. Results Fundamental frequency, average vowel formant, and sound pressure level were identified as significant predictors of masculinity–femininity ratings for these communicators. Communicators were rated significantly more feminine in the audio than the audiovisual mode and unreliably in the visual-only mode. Conclusions Both study purposes were met. Results support continued emphasis on fundamental frequency and vocal tract resonance in voice and communication modification training with transgender individuals and provide evidence for the potential benefit of modifying sound pressure level, especially when a masculine presentation is desired.

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Influence of the Acoustic Reflex on Vowel Recognition

Journal of Speech Language and Hearing Research ◽

10.1044/jshr.2903.420 ◽

1986 ◽

Vol 29 (3) ◽

pp. 420-424 ◽

Cited By ~ 4

Author(s):

Michael Dorman ◽

Ingrid Cedar ◽

Maureen Hannley ◽

Marjorie Leek ◽

Julie Mapes Lindholm

Keyword(s):

Auditory System ◽

Sound Pressure ◽

Dynamic Range ◽

Recognition Accuracy ◽

Pressure Level ◽

Acoustic Reflex ◽

The Poor ◽

Stapedial Reflex ◽

Vowel Recognition ◽

High Sound

Computer synthesized vowels of 50- and 300-ms duration were presented to normal-hearing listeners at a moderate and high sound pressure level (SPL). Presentation at the high SPL resulted in poor recognition accuracy for vowels of a duration (50 ms) shorter than the latency of the acoustic stapedial reflex. Presentation level had no effect on recognition accuracy for vowels of sufficient duration (300 ms) to elicit the reflex. The poor recognition accuracy for the brief, high intensity vowels was significantly improved when the reflex was preactivated. These results demonstrate the importance of the acoustic reflex in extending the dynamic range of the auditory system for speech recognition.

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