hot topics in noise - brooks acoustics corporation topics in noise.pdf · 6/6/2001 · hot topics...

# 1

Hot Topics in Noise

ASA 141st Meeting -- Chicago

Bennett M. Brooks, PEBrooks Acoustics Corporation

Vernon, CTwww.brooks-acoustics.com

Paper 3pID2 -- 6 June 2001

# 2

Hot Topics in Noise -- ASA June 2001

Increased public concern about

NOISEIn response, the noise technical

community has developed:• New methods for assessment• New means for control

# 3


OUTDOORSSoundscapesNatural quietTheme parks & amphitheatersInternational environmental noise policyExtreme Hearing Protection (mil aircraft)

INDOORSRoom noise descriptorsClassroom acousticsProduct sound quality

# 4


SOUNDSCAPES- Brigitte Schulte-Fortkamp

Carl von Ossietzky University Oldenburg, Germany

Interaction of people and sound

The way people consciously perceive their environment.

# 5


• Berglund (2001) - characterize residential soundscapes in three dimensions: “adverse”, “reposing” and “affective”

• Ipsen (2001) soundscape components: the context, the focus of attention, and personal knowledge/experience.

• Schulte-Fortkamp (2000) - interaction of living space and noise sources moderating effects for noise annoyance

• Hohmann (2000) - surroundscapes which demonstrate harmonic / disharmonic effects of an urban environment

• Genuit (2000) - aurally-related psychoacoustic analysesobjective description of subjectively perceived sound

• Chtouris (2001) - sound interpreted in urban environments characterized by high density of activity

• Giuliani (2001) - relationship of visual and acoustical space Soundscape analysis - improved quality environments

# 6


The moderator soundscape• A positive evaluation of the landscape reduces

annoyance of the soundscape whereas a negative evaluation of the landscape increases annoyance (Maffiolo)

• A subjective soundscape - dependent on which parts people relate to & how they relate Example: the Sunday walker will clearly have a different experience of a street than a Monday morning late-for-work bus chaser.

(Fyhri & Klaboe)

# 7


Natural Quiet• Aircraft overflights &

snowmobiles in national parks• Arctic National Wildlife Refuge

– “Loud Turbines”(Washington Post)

# 8


Theme Parks & AmphitheatersBill Cavanaugh (Cavanaugh-Tocci)

• Sound intrusion on communities

• Signal to Noise (S/N)

# 9


• Limit L1 minus L90L1 – L90 < 5 dB rarely audible

minimal complaints5 to 15 dB sometimes audible

significant complaints> 15 dB generally audible

widespread complaints

# 10


International EnvironmentalNoise PolicyLarry Finegold – (Finegold & So)

Current Status of Noise Policies in the U.S. and Europe - Implications for International

Consensus• Adverse effects of noise on people are the major purpose for

noise research and policy-making activities (i.e., “protection of the public health”)

• International economic competition (Product Sales) is becoming more important each year

• Noise exposure is still increasing around the world –problem is worst in large cities, especially transportation noise

• No international research agenda or coordinated funding • No international coordination on noise management policies•• New European noise policy initiatives will impact all countries New European noise policy initiatives will impact all countries that that

export manufactured products to Europeexport manufactured products to Europe

How does the US compare with the rest of the world?

New World Health Organization “Guidelines for Community Noise”

http:// www.who.int/peh/European Commission Initiatives – new Noise Directives (Outdoor Equipment, Environmental Noise, etc.

http://www.europa.eu.int/comm/environment/noise/http://www.europa.eu.int/comm/environment/docum/00468_en.htmhttp://www.europa.eu.int/eur-lex/en/

Real progress being made in individual countries in Europe, Asia, etc. – Japan is the leader in Asia

http://www.europa.eu.int/comm/environment/noise/

http://www.europa.eu.int/comm/environment/docum/00468_en.htm

http://www.europa.eu.int/eur-lex/en/

Community Noise:Community Noise: Guideline values IGuideline values I

Environment Environment Critical Critical LLeqeq TimeTime LLmaxmaxeffect effect [dBA] [dBA] base [h] base [h] [dBA][dBA]

BedroomBedroom Sleep Sleep 3030 88 4545disturbancedisturbance

DwellingDwelling AnnoyanceAnnoyance 5050 1616 --roomroom Speech Speech

interferenceinterferenceOutdoor Outdoor SeriousSerious 5555 1616 --(day)(day) annoyanceannoyance

SchoolSchool SpeechSpeech 3535 66 --classroomclassroom interferenceinterference

SchoolSchool SeriousSerious 5555 playplay-- --courtyardcourtyard AnnoyanceAnnoyance timetime

Current Status of Noise Policies in the U.S. and Europe - Implications for International Consensus

- - - - - - - - - - - - - - -European Commission Noise Directives

Directive on Environmental Noise

• The Environment Directorate-General has published a 26 page booklet "The Noise Policy of the European Union Year 2 (1999 - 2000)" -- explains the current scope of the proposed Directive.

• On 26 July 2000 the Commission adopted a draft proposal for a Directive on Environmental noise (COM(2000)468).

• Two readings in the European Parliament and the Council will probably lead to further changes.

http://www.europa.eu.int/comm/environment/noise/noisebrocure.pdf




http://www.europa.eu.int/comm/environment/docum/00468_en.htm


- - - - - - - - - - - - - - -European Commission Noise Directives

Directive on Noise from Equipment Used Outdoors

The administrative and legal position is given in Directive 2000/14/EC.

An ad hoc Working Group, number 7, shepherds the new Directive and helps on the old directives that are to be repealed as the new one has come into force.

http://www.europa.eu.int/comm/environment/noise/d0014_en.pdf





- - - - - - - - - - - - - - -Example European Commission Noise Directives

Environment Directorate-General• Construction Plant Equipment - 79/113/ EEC• Type Approval for Construction Plant and Equipment -

84/532/EEC• Compressors - 84/533/EEC• Tower Cranes - 84/534/EEC• Welding Generators - 84/535/EEC• Power Generators - 84/536/EEC• Concrete Breakers - 84/537/EEC• Lawnmowers - 84/538/EEC• Hydraulic Excavators - 86/662/EEC• Household Appliances - 86/594/EEC

http://www.europa.eu.int/cgi-bin/eur-lex/udl.pl?REQUEST=Seek-Deliver&LANGUAGE=en&SERVICE=eurlex&COLLECTION=lif&DOCID=379L0113













- - - - - - - - - - - - - - -Example European Commission Noise Directives

Other Directorate-Generals• Motor Vehicles - 70/157/EEC• Motor Cycles - 97/24/EC• Subsonic Aircraft - 80/51/EEC• Subsonic Jet Aeroplanes - 89/629/EEC• Limitation of the Operations of Aeroplanes - 92/14/EEC

Expected New Directives:• Tyre/Road Noise • Noise from recreational crafts








Summary – US Noise Policy-Making Efforts

• Noise must be considered as a significant environmental “Public Health” problem - Most of the world’s developed countries accept this and are making good progress on managing noise exposure

• The U.S. was once the world’s leader in addressing environmental/community/transportation noise, but this momentum has been lost

• Federal agencies and professional organizations need to make a renewed commitment to addressing noise management problems in the 21st Century– Noise effects research, noise control technologies, and noise

management policies

# 20


Extreme Hearing Protection (military aircraft)

- Richard McKinley (civ AFRL/HECB)(Wright-Patterson AFB)

Thanks to: US NavyUS Air Force

# 21

140

148

148

135

146148 15

3

144 14

9

145 15

0

143 14

6

146 15

0

148 15

2

150

0

20

40

60

80

100

120

140

160

180

Tactical Aircraft Near-Field NoiseWorst Case Aircraft Noise Levels - @ 50 ft

Soun

d Le

vel d

B

Mil Power A/B Power

Wor

se P

robl

emAV -

8BJS

F ST

OVL

est

10/

99 *

EA-6

BF-

14A

/BF-

14C

/DF-

15C

F-16

(P22

9)F-

18C

/D

F-22

JSF

CV

& C

TOL

est 1

0/99

*

F-14

A/B

F-14

DF-

15C

F-16

(P22

9)F-

18C

/D

F-22

JSF

CV

& C

TOL

est 1

0/99

*

F-18

E/F

8 hr Limit,85 dB

# 22

Aircraft Carrier Flight Deck

# 23

F-18 Cat 1 (System 6) 1018 AM

80

90

100

110

120

130

140

150

12.47

13.72

14.97

16.22

17.47

18.72

19.97

21.22

22.47

23.72

24.97

26.22

27.47

28.72

29.97

31.22

32.47

33.72

34.97

36.22

37.47

38.72

39.97

41.22

42.47

43.72

44.97

46.22

47.47

48.72

49.97

Time(s)

dBA

Launch Noise Time HistoryF-18 Mil power Bow Catapult

# 24

Carrier Near Field NoiseCrew Positioning Challenges

# 25


# 26


# 27

Carrier Personnel NoiseCrew Positioning Challenges

Checkers in front & BehindDuring Launch

Launch Crew between the CatapultsDirectors during

STOVL Operationson L-Class Ships

# 28


For 85 dBA criterion (8 hours, 3 dB doubling)

30 dB attenuation reach exposure limit7 to 30 seconds

Current program achieving improvedattenuation 38 – 40 dB

# 29


New Room Noise Criteria

- Paul Schomer - CERL

# 30

Room Noise Criteria (RNC)

• Problem--S12.2–Beranek--NCB –Blazier--RC

• Very different at low frequencies–Beranek--Well behaved HVAC as

in a concert hall–Blazier--Inexpensive “office”

HVAC. May have rumble and surging

# 31

Beranek--NCB Room Noise Criteria Curves

16 31 63 125 250 500 1 K 2 K 4 K 8 K

Octave-Band Center Frequency (Hz)

0

10

20

30

40

50

60

70

80

90

100

Soun

d Pr

essu

re L

evel

(dB

)

50

40

30

20

10

"A" Region

Threshold of Hearing

# 32

Blazier--RC Room Noise Criteria Curves

16 31 63 125 250 500 1 K 2 K 4 K 8 K


0

10

20

30

40

50

60

70

80

90

Soun

d Pr

essu

re L

evel

(dB)

50

40

30

"A" Region

Threshold of Hearing

Are Curves Below the Threshold of Hearing at Low Frequencies A Mistake?

# 33

Why The Difference Between Beranek and Blazier?

• Beranek--Concert Halls, “well designed” HVAC• Blazier--Surging, Rumbling HVAC

40

45

50

55

60

65

0 1 2 3 4 5Time (s)

31 H

z O

ctav

e B

and

SPL

LEQ = 54.5

Threshold = 55 dB

Surging = 10 dB Peak,1/2 Hz

Sigma = 3.3 dB

Is This Heard? The LEQ is Below the Threshold of Hearing.

# 34

RNC Room Noise Criteria

• Correction to NCB-like curves– A function of frequency and AMPLITUDE– Detect with fast-time-response to simulate the

integration time of human hearing – Use 1/3rd octave bands each ~100 ms– Maintain log10 arithmetic

• Find the low-frequency correction for 16, 31 and 63 Hz• Use loudness-level contour arithmetic--the hearing function at 31

Hz--5 dB change in SPL is a 10 phon change.

# 35

Proposed New--RNC (Room Noise Criteria) Curves

16 31 63 125 250 500 1K 2K 4K 8K


0

10

20

30

40

50

60

70

80

90

Soun

d Pr

essu

re L

evel

(dB)

“A” Region

# 36

A Test of New Room Noise Criteria (RNC)

• John Bradley--1994 studyNRC Canada

• 9 Subjects• Main Frequency--31 Hz

Band• Modulation Depth--10 dB,

17 dB• Modulation Frequencies:

0 (none), 0.25, 0.5, 1, 2, 4 Hz

• Results:• Difference RNC-Bradley: 1.2 dB• Standard deviation: 1.1 dB• Correlation Coefficient 0.92

• THIS SEEMS TO WORK

# 37


Classroom Acoustics Standard

- David Lubman – Consultant

# 38

Good Classroom Acoustics Is Vital to All Knowledge-based Societies

The ability to hear & be heard is central to all language based learning.– Students of all ages need good acoustics.

Lifelong learning is paramount in new world economy.

• Demanding new standards are being developed for noise and reverberation control in schools.– Higher standards expected to greatly increase

the acoustical content of future school design.– More acoustically trained architects and

mechanical engineers will be needed for the school building boom.

# 39

Inclusive vs. exclusive classroom acoustics

Good classroom acoustics are inclusive for:

• Non-native listeners and talkers.• Students & teachers with hearing or

voice impairments.• Young children & inexperienced

learners• Fatigued learners• Poorly motivated learners• Elderly

# 40

New Standards for Classroom Acoustics to Benefit All!

• ANSI S12 standard nearing completion– Draft 9 approved by S12 in spring. – Full ANSI approval of draft 10 possible by fall– Noise levels not to exceed 35 dBA– Reverberation times under 0.7 sec (small

classrooms)• New noise guideline in Alberta, Canada

– Standards & guidelines for school facilities• New HVAC noise guidelines for NYC schools• LA expected to endorse 35 dBA for new schools

# 41


Product Sound Quality

- David Bowen – R. H. Lyon Corp

# 42


WE (every acoustician)

Are All Ambassadors

For NOISE

hot topics in noise - brooks acoustics corporation topics in noise.pdf · 6/6/2001 · hot topics...

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