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Environmental Impacts, Threshold Levels and Health Effects Lecture - - PowerPoint PPT Presentation

Apr 28, 2023 371 likes •831 views

[701-0662-00 V] Environmental Impacts, Threshold Levels and Health Effects Lecture 8: Noise - Part 2 (08.04.2020) Mark Brink ETH Zrich D-USYS Homepage: http://www.noise.ethz.ch/ei/ D- USYS M. Brink Environmental Impacts - Noise

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 1

[701-0662-00 V] Environmental Impacts, Threshold Levels and Health Effects Lecture 8: Noise - Part 2 (08.04.2020)

Mark Brink

ETH Zürich D-USYS

Homepage:

http://www.noise.ethz.ch/ei/

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 2

  • Overview over Part 2 ("Noise") of the lecture
  • Physical basics: Sound pressure and

sound pressure level

  • The Decibel scale, Decibel arithmetic
  • Perceivable changes of sound pressure level
  • Anatomy of the ear
  • Principles of auditory perception
  • Basilar membrane, hair cells
  • Gestalt-principles of auditory perception

Topics covered in the previous lecture

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 3

► Physical and subjective description of sound ► Sound pressure level measurement

►

The measures SPL, Leq, Lmax, SEL (LE)

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Frequency weighting filters and Time constants

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Demonstration with Sound Level Meter

► Noise – introduction

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Transportation noise situation in Switzerland

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Noise exposure statistics in the Canton of Zurich

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Time variation of road traffic noise exposure

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Effectiveness of noise abatement measures

► Measurement and calculation of (transportation) noise

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Measurement and calculation of noise exposure

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Sound propagation and attenuation

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Noise maps / noise contours

Lecture overview for today

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 4

Physical and subjective description of sound

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 5

Physical and subjective descriptions of "sound volume"

Sound pressure level – Unit: dB Sound power level – Unit: dB Sound intensity level – Unit: dB Sound pressure

– Unit: Pa

Sound power

– Unit: W

Sound intensity

– Unit: Wm-2

Physical description Subjective description Loudness – Unit: sone Loudness level – Unit: Phon Sound

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 6

Sound pressure level at the ear [dB]

Dynamic range

0 dB = 0.00002 Pa

Auditory sensation area

Musical perception Speech perception Threshold of pain

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 7

Equal loudness curves (German "Kurven gleicher Lautstärke")

Hearing threshold

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 8

Sound pressure level: common measures

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 9

Sound pressure level measurement

Sound level meter (SLM) Calculation (sonBASE noise map)

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 10

Most common measures

SPL (Current) Sound pressure level (over time) Lmax Maximum level within measurement period LE (also called „SEL“) Sound Exposure Level (Total energy of a defined sound event) Leq Equivalent Continuous Sound Level (energetic average)

time SPL in dB

Measurement period

LE/SEL Lmax LAeq

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 11

Statistical Measures L10, L50, L90

Note that L10 > L50 > L90

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 12

Frequency weighting filters

Attenuation [dB] Frequency [Hz]

+20 +0

  • 20
  • 40
  • 60

10 100 1'000 10'000 A B C

→ "dB(A)" always means: A-weighted measurement

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 13

Time constants (FAST and SLOW)

→ LAF means: A-weighted, FAST → LAS means: A-weighted, SLOW FAST (125 ms) SLOW (1 sec)

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 14

Demonstrations with sound level meter

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 15

Noise exposure

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 16

... lets start with road traffic noise

Road traffic is the single most dominant noise source worldwide!

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 17

Course of 1h-Leq of road traffic noise over a week

1h-Leq Vehicles per hour % trucks

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 18

Diurnal variation of annual average daily traffic AADT in CH

H00 H01 H02 H03 H04 H05 H06 H07 H08 H09 H10 H11 H12 H13 H14 H15 H16 H17 H18 H19 H20 H21 H22 H23

Hour of the day

_ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Percent of AADT [%]

Median 25%-75% Min-Max

average at 307 automatic traffic counting stations

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 19

Number of vehicles per hour Leq dB(A)

25 50 75 100 125 150 175 200 225 250

30 35 40 45 50 55 60 65 70

1

3 dB

Doubling the number of events leads to an increase of 3 dB

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 20

Range of maximum sound pressure levels Lmax

(at a distance of 7.5 m)

Car Pickup/Van Bus Light truck Heavy truck Motorbike

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 21

0 dB 35 dB 40 dB 15 dB 5 dB 25 dB 30 dB 20 dB 10 dB

Encasing/encapsulation ( > 30dB ) 4 m noise barrier (10 - 15dB ) 2 m noise barrier (5 - 10dB ) Low noise pavement (1 - 5dB ) Cut traffic by half (3 dB) Speed reductions (up to 3dB)

Effectiveness of noise abatement measures

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 22

Sound attenuation outdoors – indoors

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 23

Sound attenuation outdoors – indoors Sound-proof windows 30-40 dB attenuation

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 24

Tires Engine vibrations Fan Air intake and muffler Power train

Three types of sources:

  • Engine and transmission noise:

dominant during acceleration, in low gears

  • Tire/road noise:

dominates on community roads and highways

  • Aerodynamic noise:
  • nly at high speeds

Road traffic as noise source

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 25

Ripples on rails Railways as noise source

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 26

Railways as noise source

Cast iron brake pad Synthetic brake pads Disk brake

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 27

Flaps Landing gear Engines

Aircraft as noise source

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 28

Noise footprints at landing and take off

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 29

Brüel&Kjaer 2236 Integrating precision sound level meter CADNA-A calculation of exposure contours on the computer

Measurement and calculation of noise exposure

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 30

LW

Distance source-receiver

LAE Receiver Source

Traffic figures, Radar tracks etc..

LAeq

Calculation of noise exposure

Basic principles

Emission Immission

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 31

Measurement of sources with microphone arrays acoustic camera

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 32

Measurement of sources with microphone arrays

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 33

Influence of wind and temperature gradient

cold warm warm cold Day Night

Sound propagation

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 34

Airport Temperature ± 1 dB Wind ± 5 dB Humidity ± 1 dB Throttle pos. ± 1 dB Attenuation Reflections Situational conditions

Influencing factors in sound propagation

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 35

  • Leq

This is the basic measure: Average level over a certain time period

  • Leq,24 h

Average level over 24 hours, 00-24 h

  • LDay

Leq in the period 07-23 h (Switzerland 06-22 h)

  • LNight

Leq in the period 23-07 h (Switzerland 22-06 h)

Most frequently used average measures of noise exposure

used in noise legislation in CH (partly), the EU, the US...

  • LDN (DNL)

Day-Night Level: L07-22h + 0 dB L22-07h + 10 dB penalty

  • LDEN (DENL)

Day-Evening-Night Level: L07-19h + 0 dB L19-23h + 5 dB penalty L23-07h + 10 dB penalty

"Noise metrics"

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 36

Most frequently used average measures of noise exposure

Formulas for Leq,24 h , LDN , and LDEN

( ) ( )

 

        

07-22h 22-07h

0.1 Leq +0 0.1 Leq +10 DN

15 9 L =10 lg 10 + 10 24 24

( ) ( ) ( )

  

        

eq,07-19h eq,19-23h eq,23-07h

0.1 L +0 0.1 L +5 0.1 L +10 DEN

12 4 8 L =10 lg 10 + 10 + ×10 24 24 24

( ) ( )

Day Night

0.1 L 0.1 L eq,24 h

16 8 L =10 lg 10 + 10 24 24

 

      

used in USA used in EU

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 37 50'000 100'000 150'000 200'000 250'000 300'000 350'000 400'000 40 45 50 55 60 65 70 75 80

Number of people Exposure in dB(A)

L_day L_night L_den L_dn

Distribution of noise levels in Switzerland (Year 2010) Road traffic noise

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 38

Distribution of noise levels in Switzerland (Year 2010) Railway noise

20'000 40'000 60'000 80'000 100'000 120'000 140'000 160'000 180'000 200'000 40 45 50 55 60 65 70 75 80

Number of people Exposure in dB(A)

L_day L_night L_den L_dn

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 39

1-Stunden-Leq von 55 dB

N

Noise exposure contours on a map

Auckland, NZ

Auckland, NZ

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 40

Road traffic noise map

Sursee, Kanton Luzern

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 41

Road traffic noise map

Brussels, Belgium

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 42

Road traffic noise during day sonBASE (Swiss noise mapping database)

80 dB(A) 0 dB(A)

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 43

Rail traffic noise during day sonBASE (Swiss noise mapping database)

80 dB(A) 0 dB(A)

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D-USYS • M. Brink • Environmental Impacts - Noise Part 2 Slide 44

Aircraft noise sonBASE (Swiss noise mapping database)

Zurich Airport Euro Airport Basel Geneva Airport

Payerne (Air Force) Sion (Air Force) Meiringen (Air Force)