Survey of interior noise characteristics in various types of trains

doi:10.1016/j.apacoust.2013.04.002

Applied Acoustics

Volume 74, Issue 10, October 2013, Pages 1160-1166

https://doi.org/10.1016/j.apacoust.2013.04.002 Get rights and content

Abstract

The aim of this paper is to determine the effects of the wheel-rail friction, motor and tires on noise characteristics in a train car. The octave-band power levels, A-weighted equivalent continuous sound pressure level and parameters extracted from interaural cross-correlation/autocorrelation functions were analyzed to evaluate the noise inside running train cars quantitatively and qualitatively. The three types of noise caused by wheel-rail interaction are rolling, impact, and curve squeal noises. Impact noises had larger components at lower frequencies (< 1000 Hz). Curve squeal noises had larger components at frequencies between 125 and 500 Hz in both underground and surface trains and had dominant frequency components around 250 and 500 Hz with stronger pitch in underground trains. High-speed trains had low-frequency centroids and high binaural coherence compared with normal-speed trains.

Introduction

The sound quality in train cars is an important concern for the railway industry since many people use trains for long periods of time. For example, approximately 40% of commuters use trains, with an average commuting time of more than 140 min (round trip), in a typical metropolitan area of Japan such as Tokyo. The fundamental issue is to create a comfortable acoustic environment in a train car for the passenger. The train industry has succeeded in lowering the equivalent sound-pressure level (SPL) in train cars to a mean of less than 70 dBA [1], [2], [3]. However, lowering the SPL is not enough for a comfortable acoustical environment. Even when the SPL is only about 35 dBA, people may feel annoyed by conditions such as fluctuations of pitch and a localized sound source [4].

People hear various types of noise in train cars. Researchers have studied mechanisms for generating different types of noise such as rolling, impact, curve squeal [5], [6], [7], [8], [9], motor (fans) [10], [11], and aerodynamic noises [12], [13]. Some studies have modeled the noise in train cars to help predict and reduce it [14], [15], [16], [17]. Although some studies have quantitatively [1], [2], [3], [18], [19], [20], [21] and qualitatively [2], [3] investigated the noise characteristics inside running train cars, the effects of noise sources on the noise characteristics have not been evaluated qualitatively. This should be clarified to improve the acoustical environment in a train car for the passenger.

The aim of this study is to clarify the effects of noise sources on the noise characteristics inside running train cars. In particular, we focus on the effects of the rolling, impact, curve squeal, and motor (fans) noises inside train cars. Acoustic treatment (i.e., sound absorption, insulation, and active noise control) is an effective solution for improving the sound environment inside train cars. To consider an appropriate acoustic treatment, it is necessary to clarify the characteristics of the noise inside train cars.

Section snippets

Measured trains

We continually measured noise in a train car traveling from one terminal station to another terminal station on 15 lines. Different types of train car were run on each line. Table 1 lists the location, main motor, maximum speed, average speed, number of intervals, and number of curves measured. Active noise control is not installed in the train car. We classified trains according to location (surface and underground), main motor (linear or three-phase induction motor), and speed (normal and

Effect of wheel rail interaction (rolling, impact, and curve squeal)

Fig. 2 shows the averaged L_Aeq and octave band levels for rolling, impact, and curve squeal noises in running surface and underground trains. Impact noises had larger components at lower frequencies (less than 500 Hz) compared with rolling noises in both underground and surface trains. Curve squeal noises had larger components at frequencies higher than 125 Hz in underground trains and at frequencies between 125 and 500 Hz s in surface trains compared with rolling noise. Underground trains often

Conclusions

We analyzed the effects of the rolling, impact, curve squeal, and motor (fan) noises on noise inside train cars. The results show the following:

1.
Impact noises had larger components at lower frequencies (less than 500 Hz) compared with rolling noises.
2.
Curve squeal noises had larger components at frequencies above 125 Hz, which have stronger pitch, in underground trains and at frequencies between 125 and 500 Hz in surface trains compared with rolling noises.
3.
Curve squeal noises had longer τ₁ values

Acknowledgments

We thank the railroad staff who cooperated in our measurements. This work was supported by a Grant-in-Aid for Young Scientists (A) from the Japan Society for the Promotion of Science (No. 23686086).

References (45)

A.E. Hardy
Measurement and assessment of noise within passenger trains
J Sound Vib
(2000)
P.J. Remington
Wheel/rail squeal and impact noise: what do we know? What don’t we know? Where do we go from here?
J Sound Vib
(1987)
C.J.M. van Ruiten
Mechanism of squeal noise generated by trams
J Sound Vib
(1988)
D.J. Thompson et al.
A review of the modelling of wheel/rail noise generation
J Sound Vib
(2000)
C. Mellet et al.
High speed train noise emission: latest investigation of the aerodynamic/rolling noise contribution
J Sound Vib
(2006)
B. Schulte-Werning et al.
Research on noise and vibration reduction at DB to improve the environmental friendliness of railway traffic
J Sound Vib
(2006)
K. Nagakura
Localization of aerodynamic noise sources of Shinkansen trains
J Sound Vib
(2006)
L.M. Cleon et al.
Aero-acoustic optimization of the fans and cooling circuit on SNCF’s X 72500 railcar
J Sound Vib
(2000)
M.G. Dittrich et al.
The Harmonoise/IMAGINE model for traction noise of powered railway vehicles
J Sound Vib
(2006)
J. Forssén et al.
Modelling the interior sound field of a railway vehicle using statistical energy analysis
Appl Acoust
(2012)

P.W. Eade et al.

Railway vehicle internal noise

J Sound Vib

(1977)

Y. Ando

A theory of primary sensations and spatial sensations measuring environmental noise

J Sound Vib

(2001)

H. Sakai et al.

Measurement of regional environmental noise use of a PC-based system. An application to the noise near airport “G. Marconi” in Bologna

J Sound Vib

(2001)

K. Fujii et al.

Acoustical properties of aircraft noise measured by temporal and spatial factors

J Sound Vib

(2001)

J.Y. Jeon

Subjective evaluation of floor impact noise based on the model of ACF/IACF

J Sound Vib

(2001)

H. Sakai et al.

Diagnostic system based on the human auditory-brain model for measuring environmental noise – An application to railway noise

J Sound Vib

(2002)

J.Y. Jeon et al.

Annoyance caused by heavyweight floor impact sounds in relation to the autocorrelation function and sound quality metrics

J Sound Vib

(2008)

R. Shimokura et al.

Characteristics of train noise in ground and underground stations with side and island platforms

J Sound Vib

(2011)

S. Sato et al.

Annoyance of noise stimuli in relation to the spatial factors extracted from the interaural cross-correlation function

J Sound Vib

(2004)

Y. Moritoh et al.

Noise control of high speed shinkansen

J Sound Vib

(1996)

S. Sato et al.

Loudness of sharply 2068 dB/octave filtered noises in relation to the factors extracted from the autocorrelation function

J Sound Vib

(2002)

Y. Soeta et al.

Comparison of noise characteristics in airplanes and high-speed trains

J Temp Des Archit Environ

(2009)

Cited by (34)

Carriage interior noise-based inspection for rail corrugation on high-speed railway track
2022, Applied Acoustics
The presence of rail corrugation enlarges the wheel-rail impact and exacerbates the failure of track components, and the situation becomes even worse under high train speed, which promotes the urgent need for an efficient and easily accessible inspection method. Conventional diagnosis approaches such as axle box acceleration (ABA) and image recognition measurements, however, require complex instrumentations on the running gear, restricting their applications on a wide range of operational trains. In this study, we investigate the capability of carriage interior noise in diagnosing rail corrugation on the high-speed railway (HSR). For this purpose, train-borne vibration & noise measurements were integrated with in-situ rail surface irregularity tests, to extract the characteristic carriage interior responses induced by rail corrugation. The measurements were conducted on two HSR tracks with different corrugation geometries, and the time–frequency distributions of interior noise were identified under different train speeds and with different track radii. Afterward, an interior noise-based inspection algorithm was proposed by proper correlation of the gained data, and was then demonstrated on a third HSR track with an unknown rail surface condition. The comparison between the proposed inspection algorithm and the widely-recognized ABA measurements indicates that the interior noise succeeded in identifying the position, typical wavelength and severity of rail corrugation under varying train speeds. The work advances a cost-effective and easily accessible way for the condition monitoring of railway tracks.
Evaluation and optimization of sound quality in high-speed trains
2021, Applied Acoustics
Citation Excerpt :
Although the A-W SPL mimics the subjective perception of human ears, it is often inconsistent with perceptions of uncomfortable sounds, especially non-uniformly distributed sounds, changing sounds, or deep or sharp sounds [20]. The interior noise of a high-speed train is typically composed of medium and low frequencies [21]. Traditional A-W SPL cannot objectively describe the auditory experience of human ears [22]; moreover, modern psychoacoustics indicate that physical parameters alone cannot describe passenger comfort [23], and sound pressure level is a poor indicator of noise perception by the human ear [24–26].
The rapid development of high-speed railways has been tempered by various technical challenges. As more high-speed lines carrying more high-speed trains have opened in China, abnormal train noise has become an intermittent problem, affecting the quality of high-speed trains and the subjective comfort of passengers and crew. To mitigate the abnormal noise in the conductor room of a high-speed train, this paper proposes a method for evaluating and optimizing the sound quality (SQ) inside a high-speed train. First, the vibrational noise in the train was tested and analyzed under passenger-carrying operating conditions. Second, the SQ was objectively evaluated by quantifying the interior noise with one traditional physical acoustic parameter and six psychoacoustic parameters. In a statistical analysis of a subjective listening questionnaire, the low-frequency noise was best described by a verbal expression (the Dichen descriptor in Chinese), which serves as an evaluation index in jury tests. A subjective jury (30 participants) scored the values of various sound samples. Although the A-weighted sound pressure level (A-W SPL) in the conductor room was relatively small, it was perceived as extremely irritating. The auditory perception of the human ear was not objectively described by the traditional A-W SPL, but was quantified by the psychoacoustic parameter evaluation. In a correlation analysis of the subjective and objective evaluations, the correlation coefficient between tonality and the Dichen sensation was 0.983. The tonality is the key parameter of perceived SQ in high-speed trains. Therefore, an objective quantitative model of the subjective Dichen sensation was established through multiple linear regression theory with tonality as a variable. To determine the source of the discomforting noise, the vibro-acoustic characteristics in the conductor room were analyzed and a finite element analysis of the end wall was performed. The abnormal noise was traced to a high-intensity 40-Hz pure tone caused by an externally sourced structural modal excitation near the end wall. Based on hybrid finite element–statistical energy analysis, a vibro-acoustic radiation simulation model of the end wall was established. After optimizing the end-wall structure, the SQ in the high-speed train was significantly improved. The optimization effect was verified in a noise test conducted in the interior of a real high-speed train, and in a vibro-acoustic radiation simulation model. Our results can guide the evaluation and optimization of SQ in high-speed trains.
Acoustic performance enhancement in a railway passenger carriage using hybrid ray-tracing and image-source method
2020, Applied Acoustics
Citation Excerpt :
The main and reflected sounds interfere together, and gradually the acoustic field becomes diffused. This leads to an uneven distribution of energy and sound decay along the length of the corridor and cabins [7,8]. So this is not as straight-forward as the well-known theories interpreting the sound distribution in regularly shaped rooms.
Geometry of cabins, corridors, and materials used in railway passenger carriages can play important roles in acoustic performance inside the rail cars. In order to evaluate the noise level inside a rail car, a hybrid method based on the ray-tracing and image-source techniques is employed. A parametric model is constructed based on the field experiment performed in a typical coach cabin namely Fadak train in Iranian Railway. An Omni-directional sound source inside the passenger carriage is employed inside the cabin once for an unequipped cabin and once for operational one. Acoustic parameters such as reverberation time (T30), Center time (Ts), and the sound pressure level have been calculated and results are validated with experimental acoustic measurements. The model is experimentally calibrated and then acoustics performance of the passenger coach is enhanced by modifying the materials and absorption coefficients against two dominant sound sources in low to middle speed ranges. It is found the simple recommendation can remarkably enhance the acoustic performance over a broad range of frequencies.
An acoustic design procedure for controlling interior noise of high-speed trains
2020, Applied Acoustics
Citation Excerpt :
It can be concluded that under sufficiently bad wheel/rail surface conditions, rolling noise is still dominant even at high speeds. Soeta and Shimokura [17] researched the effects of noise sources on the interior noise characteristics in various types of trains. Fan et al. [18] used the sound intensity and partial coherence methods to identify the most significant sources of interior noise.
Excessive interior noise in high-speed trains affects riding comfort of both drivers and passengers, therefore, it is a key indicator of product competitiveness for manufacturers. Past academic researches on train interior noise control focus primarily on mechanisms and characterisations of noise sources and vibro-acoustical behaviours of car-body structures, and these two aspects are often dealt with separately, unable to lead a systematic procedure for controlling high-speed train interior noise. On the other hand, many practical studies are problem-based, aiming at finding root causes of, and remedies for, a noise problem which has already occurred. They not only lack of systematisms, but also are time- and resource-consuming. To design low interior noise and to make sure the actual product based on the design does meet noise target, an acoustic design procedure is needed. Based on the experience of many years’ research in the field of railway noise and vibration, especially that gained in the development of the Chinese ‘Fuxing’ high-speed trains, such an acoustic design procedure for interior noise is summed up and described in this paper. Application of the procedure to the development of a to-be made high-speed train is also presented, together with results simulated and measured on the developed train, showing that the design goal of 3 dBA noise reduction is met.
Spatial aspects in urban soundscapes: Binaural parameters application in the study of soundscapes from Bogotá-Colombia and Brasília-Brazil
2019, Applied Acoustics
Acoustic environment studies traditionally use monaural energetic parameters as the main acoustic descriptors, which are associated with acoustic comfort and/or noise annoyance. However, under the soundscapes paradigm, it is necessary to explore other acoustic parameters that characterize not only energy levels but also temporal and spatial aspects of the acoustic environments. This paper’s goal is to deepen the study of urban soundscapes, considering the sound sources’ variation in the horizontal plane and determining the relationship of this phenomenon with subjective and descriptive aspects. The objective and subjective aspects of 10 soundscapes in the cities of Brasília (Brazil) and Bogotá (Colombia) were evaluated using fragments of binaural sound recordings. For objective analysis related to spatial behavior of sound sources, Interaural Cross-correlation Functions (IACF) in running and long-term modalities were applied to obtain the Interaural Cross-Correlation (IACC), the Interaural Time Delay (τ_IACC) and Width of IACC (w_IACC). The subjective assessment laboratory tests involved a panel of 25 listeners to evaluate different perceptual attributes and descriptive aspects of the soundscapes. The results indicate that there is a correlation between some binaural parameters derived from the running IACF and different perceptual attributes. Thus, spatial aspects, such as the variation of the sound sources in the horizontal plane, may have implications on perceptual attributes.
Sensory evaluation of the sound of rolling office chairs: An exploratory study for sound design
2018, Applied Acoustics
Only an infinitesimal part of the sounds from everyday objects that surround us has been designed specifically. This study has dealt with a sensory test for sounds produced by objects interacting with other objects, which can be performed during the concept design phase, where only some parts of the product can be tested. The aim of the study has been to prove the reliability of this preliminary test and compare it to the full-product test condition. The concept for an office-chair was considered, and the sound of a chair-wheel moving across flooring tiles was tested as a simplification of chair-flooring interactions. Sixty participants took part in a listening test and described the acoustic stimuli of the wheels of two office chairs, one of high quality and the other of low quality, rolling over polyvinyl chloride (PVC), ceramic and wood floorings. The listeners were asked to assign descriptors to stimuli from a list of 26 adjectives, according to a forced ordered scale. Comparisons were made with sounds from the rolling of real office chairs. The sound of wheel rolling was prevalently judged “rough” on ceramics, “dull” on PVC and “smooth” on wood, and some cross-modal audio-tactile verbal interactions between the sounds and flooring surfaces emerged. No statistically significant difference was found between the concept and full product test conditions, thus proving the efficacy of the concept sound test during the early design phase.

View all citing articles on Scopus

View full text

Survey of interior noise characteristics in various types of trains

Abstract

Introduction

Section snippets

Measured trains

Effect of wheel rail interaction (rolling, impact, and curve squeal)

Conclusions

Acknowledgments

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

Appl Acoust

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

J Sound Vib

Comparison of noise characteristics in airplanes and high-speed trains

J Temp Des Archit Environ