Rolling Stock Acoustics Testing

Locate, characterize and simulate the noise caused by trains as part of a type approval process.

Tests objectives :

• Characterize noise emitted by vehicles
• Characterize infrastructure (rail roughness and decay rate)
• Characterize rail traffic noise
• Investigate: Locate and characterize noise sources (power and direction) on rolling stock – whether stationary or in motion
• Simulate passing noise, rolling noise and traffic noise

Tests facilities :

• Acoustic antenna
• Masts measuring up to 40m high
• Multi-channel data acquisition device (100 channels)
• Microphone metering system (Class 1)
• Sound level meter (Class 1)
• Measuring device for rail and wheel roughness
• Sound intensity probe
• Portable analyzer
• Independent measuring system
• Simulation tools: Twins, Vampass, Mithra Fer

Accreditations :

ISO/IEC 17025 awarded by COFRAC

Testing norms :

NF EN ISO 3095 – Acoustics – Measurement of noise emitted by railbound vehicles

NF S31-088 -Acoustics – Measurement of railway traffic noise for purposes of characterization

French order of 8 November 1999 – Railway infrastructure noise

French order of 19 March 2012 – Objectives, methods, safety indicators and safety and interoperability regulations applicable on the French rail network

Technical Specifications for Interoperability

Verify the compliance of noise levels emitted by a vehicle with the specifications and standards in force.

Tests objectives :

Measure outside and/or inside noise emitted by stationary or rail vehicles for commissioning purposes or for approval of adaptations.

Tests facilities :

• Integrating sound level meters (SOLO type – 01dB Metravib)
• Sound calibrators (Bruel & Kjaer)
• Microphone conditioner (Brüel & Kjaer)
• Multichannel conditioning (Brüel & Kjaer, Nexus type)
• Multi-channel data acquisition device (NETDB model, 01dB-Metravib – 4 to 16 channels)
• Software: dBTrait, dBFA

Testing norms :

NF EN ISO 3095 – Acoustics – Measurement of noise emitted by railbound vehicles

NF S31-007 – Acoustics – Measurement of noise emitted by accelerating road vehicles – Engineering method

NF S31-086 – Acoustics – Measurement of noise inside road vehicles (public transport)

NF EN ISO 3381 – Acoustics – Measurement of noise inside rail vehicles

Qualify, characterize and simulate acoustics inside trains or premises.

Tests objectives :

• Qualify rolling stock: Indoor noise during running, deceleration and stopping, reverberation time, signal audibility, speech intelligibility
• Evaluate speech intelligibility on board trains through the Speech Transmission Index (determined by measurement of the modulation transfer function, impulse response and values of “speech level/noise level measured” or directly by pseudo-random sequences)
• Characterize rooms: Room criteria, impulse response, speech intelligibility, wall transparency
• Investigate: Vibroacoustics, psychoacoustic criteria, audibility of safety signals, acoustic characteristics of sources
• Simulate acoustics of premises: Modelling and improvement
• Determine the threshold of audibility

Tests facilities :

• Sound level meters (Class 1)
• Multi-channel data acquisition device
• Sound level meter system (Class 1)
• Omnidirectional sources
• Artificial mouth
• Calculation software for psychoacoustic criteria
• Sound intensity probe
• Acoustic test chamber
• Statistics calculator software
• Simulation software

Accreditations :

ISO/IEC 17025 awarded by COFRAC

Testing norms :

NF EN ISO 3381 – Acoustics – Measurement of noise inside rail vehicles

NF EN ISO 3382-2 -Acoustics – Measurement of room acoustic parameters – Part 2: Reverberation time in ordinary rooms

NF S31-088 -Acoustics – Measurement of railway traffic noise for its characterization

NF EN 60268-16 – Sound system equipment – Part 16: Objective rating of speech intelligibility by speech transmission index

Technical Specifications for Interoperability – Rolling stock: Conventional rail, High speed