1. 1Directional Sound Performance Directional Sound Performance Testing Scott Lang Mike Dybas

2. 2Directional Sound Performance What is directional sound? Codes and standards status Testing Recommendations Agenda

3. 3Directional Sound Performance What is Directional Sound?

4. 4Directional Sound Performance Audible notification appliances are intended to alert occupants of a hazardous situation Directional sounders are audible devices that are intended to guide a person from an unsafe area to a safe area Called “Exit Marking Audible Notification Appliances” by NFPA 72 (3.3.160.1.1) Audible Notification Appliances

5. 5Directional Sound Performance Changes in fuel load have decreased escape time Numerous cases of crowding at exits during an emergency Supplement visible means of marking exits Visible exit markings can be obscured by smoke Visually impaired occupants have limited guidance during building evacuation “Learned irrelevance” of existing signage Why Directional Sounders?

6. 6Directional Sound Performance …but what about occupant evacuation time? Fire Detection to Occupant Evacuation Technology has improved fire system activation time…

7. 7Directional Sound Performance Directional Sound Codes and Standards Status

8. 8Directional Sound Performance Exit Marking Audible Notification Appliances first included in NFPA 72: 2007 Currently in section 18.4.7 Details how they should be installed and minimum device requirements for frequency and sound pressure level There is no product standard for listing purposes. NFPA 72 ® and UL

9. 9Directional Sound Performance BS 8456: 2005: Code of practice for design and installation of directional sounder evac systems PAS 41: 2003: Directional Sounders – Requirements and Tests Developed for BSI committee FSH/12/5 (Alarm devices, voice alarm evacuation sub-systems and emergency voice communications) A Publicly Available Specification (PAS) is a sponsored fast- track standard driven by the needs of the client organizations and developed according to guidelines set out by BSI. Typically reviewed after two years British Standard

10. 10Directional Sound Performance Describes 18 possible tests Shock Impact Corrosion, etc. Only the localization test was reproduced in our testing Establishes a subject-based measurement of directionality Similar to intelligibility tests A group of ten test subjects must identify the correct location greater than 75 percent of the time PAS 41 Requirements

11. 11Directional Sound Performance Goal was to demonstrate a method for determining whether a sound is directional Can subject-based methods be used? Avoid purely technical criteria What are the potential pitfalls? Can we use the method in a product standard? Research Goal

12. 12Directional Sound Performance Directional Sound Testing

13. 13Directional Sound Performance 36 identical sounders placed in a circle around a test subject Only certain sounders are operational (unknown to subject) Subject is 3 meters from each sounder Sounders are 1.2 meters from the floor Sounders are set to 85 dBA min. Localization Test Set-Up

14. 14Directional Sound Performance “Focus on the front unit during the test and do not move your head while the test unit is active!” Record Diagram

15. 15Directional Sound Performance Directional Sounder Mounts

16. 16Directional Sound Performance Sounder Locations

17. 17Directional Sound Performance Room is slightly reverberant Less than 1 meter behind some sounders 22 by 36 feet (15 foot ceiling) Some tests conducted with sounders set to less than 85 dBA Age distribution of subjects Differences with PAS 41

18. 18Directional Sound Performance Do not move your head A sound/tone will be played a number of times You will be required to identify the exact location of the sound The sound will be played 18 times for 10 seconds with a gap of 5 seconds between each sound Test Subject Briefing

19. 19Directional Sound Performance All notification appliances were System Sensor products Ambient sound level − 59 dBA ExitPoint® Directional Sounder − 87 dBA peak Chime set to whoop tone (frequency sweep) − 73 dBA peak Standard 2-4 kHz nominal temporal-3 sounder − 87 dBA peak 3 kHz pure tone temporal-3 mini sounder − 91 dBA peak Products Tested: Phase 1 & 2

20. 20Directional Sound Performance Active Sounders Active sounders were unknown to the test subjects

21. 21Directional Sound Performance Tom This subject was very accurate. Test Result Example 1

22. 22Directional Sound Performance John This subject was less accurate. Test Result Example 2

23. 23Directional Sound Performance In Phase 1, localization test performed exactly as the standard describes. Phase 1 Results % correct = total # correct identifications/(# subjects * 18) Min % and max % are the percent of correct responses from one individual ProductCorrect %Min. %Max. % ExitPoint36661 Chime (Whoop) 18044 Std. Sounder (T-3) 19639 Mini horn (T-3) 7022

24. 24Directional Sound Performance Is it realistic that the subject would not turn to face the sound? Phase 1 was repeated, allowing subjects to rotate their chair Sounders were numbered After each sound, subject returned to “home” position Phase 2 Overview

25. 25Directional Sound Performance Allowing subjects to rotate in their chairs greatly improves the results. Phase 1 & 2 Results Product % Correct Ph. 1 % Correct Ph. 2 ExitPoint3690 Chime (Whoop)1855 Std. Sounder (T-3)1969 Mini horn (T-3)727

26. 26Directional Sound Performance Subjects still allowed to rotate in the chair Added competing sounds: Standard sounder in T-3 (87 dBA) Mini horn in T-3 (91 dBA) 520 Hz sounder in T-3 (92 dBA) Competing sounder was mounted about 3.1 meters to subject’s right Phase 3 Overview

27. 27Directional Sound Performance Competing sounds diminish subject’s ability to localize sound. Phase 1 Results Product Competing Sound Percent Correct ExitPointStandard sounder87 ExitPoint520 Hz77 ExitPointMini horn78 ExitPointNone (Phase 2)90 WhoopStandard sounder45 Whoop520 Hz44 WhoopMini horn29 WhoopNone (Phase 2)55

28. 28Directional Sound Performance Different types of sounders vary widely in their ability to produce directional sound Competing sounds do diminish subject’s ability to localize sound PAS 41, with modifications, could be used for listing directional sounders Test Conclusions

29. 29Directional Sound Performance Standard Recommendations

30. 30Directional Sound Performance Allow the test subjects to rotate in the chair; number sounders Add provision in standard to test for competing sounds Allow any of the 36 sounders to be activated Standard Recommendations

31. 31Directional Sound Performance Assess repeatability and reproducibility Move PAS 41 forward to become a full BSI standard Include PAS 41 into EN 54-3 Adapt PAS 41 for inclusion into UL 464 General Recommendations

32. 32Directional Sound Performance Directional Sound Performance Findings Questions & Comments