Hello Doug, depending on your environment or application, a difference of 3 to 6 dB SPL may not be sufficient. For example, the "Guidelines for Auditory Warning Systems on Civil Aircraft" (CAA Paper 82017) by Patterson recommend a difference of 15 to 25 dB SPL to ensure that an acoustic warning is not missed. If the spectrum of the ambient noise can be assumed as steady and is known or can be estimated, the SPL of a narrow-band acoustic warning should be adapted to the noise level in this frequency band to avoid excessive noise levels (see Figure 1 in the online article below).
Besides sound pressure level, also localizability (if the warning is emitted by a device needing attention) and perceived urgency of the warning (if different warnings that require different reactions may be emitted) should be considered in the design. More details can be found in the book "Warning design: A research prospective" by Edworthy and Adams or online in the article: Edworthy J, Hellier E. Auditory warnings in noisy environments. Noise Health [serial online] 2000 [cited 2017 Feb 7];2:27-39. Available from: http://www.noiseandhealth.org/text.asp?2000/2/6/27/32649 Kind regards, Bernd Von: Doug Powell [mailto:doug...@gmail.com] Gesendet: Dienstag, 7. Februar 2017 00:58 An: EMC-PSTC@LISTSERV.IEEE.ORG Betreff: [PSES] Acoustic Warning - sound pressure level All, I recall some time ago reading information on minimum sound pressure level for acoustic warning in noisy environments. It was possibly in an IEC standard or a handbook making recommendations. As I recall the recommendation was something like warning bells, horns and klaxons should be 3 to 6 dB SPL above the ambient noise level in the immediate work area. If this is not possible or operators may be wearing hearing protection, then visual warnings should also be included. Can someone point me in the right direction? Thanks, Doug -- Douglas E Powell mailto:doug...@gmail.com http://www.linkedin.com/in/dougp01 - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> ________________________________ WILO SE Nortkirchenstrasse 100, 44263 Dortmund Amtsgericht Dortmund, HRB 21356 www.wilo.com Vorstand/Executive Board: Oliver Hermes (Vorsitzender/Chairman), Dr. Markus Beukenberg, Carsten Krumm, Eric Lachambre, Mathias Weyers Aufsichtsratsvorsitzender/Chairman of the Supervisory Board: Prof. Dr. Norbert Wieselhuber Dieses Dokument ist vertraulich zu behandeln. Die Weitergabe sowie Vervielfaeltigung, Verwertung und Mitteilung seines Inhalts ist nur mit unserer ausdruecklichen Genehmigung gestattet. Alle Rechte vorbehalten, insbesondere fuer den Fall der Schutzrechtsanmeldung. This document has to be treated confidentially. Its contents are not to be passed on, duplicated, exploited or disclosed without our expressed permission. All rights reserved, especially the right to apply for protective rights. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
