cen:proj:82002

Railway applications - Acoustics - Measurement and assessment of audible signals in the driver’s cab cen:proj:82002

Scope

This document specifies procedure to measure and assess audible information in the driver’s cab for heavy mainline rail and urban rail system.
• This document specifies some measurement methods for:
o Background noise measurement(s) in cab in accordance with EN ISO 3381
o Measurement of audible signals with fixed sound levels (not dependent on conditions, e.g. speed or power)
o Measurement of varying signal sound levels from adaptive systems (levels dependent on background noise levels which vary with, e.g., speed or power)
• This document establishes the audibility of signal by providing:
o A methodology for their assessment (using e.g. EN ISO 7731, Detectsound or alternative methods)
o A simplified solution to obtain a first result by an optional use of transfer function method
• This document gives guidance guidance on
o Hearing perception (recommended lower and upper limits for sound levels and frequencies based on hearing ability)
o Signal design (device, number of frequency components, amplitudes and frequencies of components and signals; use of pulsed, continuous or intermittent signals)
o Procedure for presenting audible signals if two (or more) are needed simultaneously, dealing with priority
o Compatibility of new and existing (legacy) signals to avoid confusion
o Assessment of new or existing signals for audibility
• Importance of the signal and its classification in terms of urgency (alarm or information signal)

The following applies to this standard:
— this document refers to acoustical signals to present information and emergency messages to the driver
— this document is applicable to tonal and complex tonal signals with defined frequency components levels and pulse sequences;
— this document is applicable to prerecorded spoken signals
This document is not applicable to:
— Two-way spoken communication (e.g radio, phone)
— Audible signals or announcements for passengers in the passenger compartments
— Signals from outside the train, e.g. chimes and public address announcements to passengers waiting at a station.