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RumsakustikErling Nilsson, AkustikerECOPHON Saint-Gobain

Community school no 15, Gdynia, Poland. Architect: Adam Drochomiercki. Photo: Szymon Polanski.System: Ecophon Master A/alpha

Production unit Distribution center

European supply chain

Forssa

A sound effect on people Our mission and vision The Ecophon Story Company facts Part of Saint-Gobain Care for environment

Our way to the market Products and systems References EndingMarket segments Production and logistics

Næstved

Hyllinge

Gliwice

Chalon

Saint-Gobain• One of the world’s 100 leading industry groups• Focusing on habitat and construction• Established in 1665• Present in 64 countries• 190 000 employees• ~ €40 billion in sales

Spegelsalen i Versailles

Four market segments

• Long experience of how sound affects people• Specialised knowledge about segment specific activities• Systems developed for specific needs

Education Modern Office Healthcare Clean Industry

Benefits of good acoustics

• Increased wellbeing and satisfaction• Less tiredness• Easier to concentrate• Fewer errors• Less stress hormones• Easier to communicate• More positive energy• Increased creativity

Innehåll

• Något om Ecophon• Rumsakustik i praktiken• Betydelsen av god akustik• Rumsakustik och ljudabsorption• “Activity based acoustic design”• Rumsakustiska mått• Effekt av akustikreglering I klassrum• Öppna kontorslandskap• Några exempel på akustikreglering

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Room Acoustic design in practise

Schools:

Positive effects of a good sound environment in educational premises include:

• Reduced vocal strain and voice disorders for teachers• Improved concentration• Reduced tiredness, fatigue and stress levels• Easier to hear and be heard with improved speech clarity• Optimised environment for multi-communicational activities such as group work• Improved student behaviour and reduced burden on school and classroom

management

Healthcare:

Better sound environment contributes to:

• Lowering of blood pressure• Improving quality of sleep• Reducing intake of pain medication• Reducing the number of re-admissions• Improving the wellbeing of staff and increasing perceived performance

Open-plan offices:

• In a modern flexible OPO, the creation of a functional work station is a complex process in which acoustic planning is only one part of a series of considerations having to be addressed. The open-plan office should support both communication and concentrated work. Thus, for an OPO to be an efficient and comfortable place of work there are several other requirements than acoustic treatment that have to be fulfilled.

Public health experts agree that environmental risks

constitute 24% of the burden

of disease. Widespread exposure to environmental

noise from road, rail, airports

and industrial sites contributes to this burden. One in

three individuals is annoyed

during the daytime and one in five has disturbed

sleep at night because of traffic

noise. Epidemiological evidence indicates that those

chronically exposed to high levels

of environmental noise have an increased risk of

cardiovascular diseases such as

myocardial infarction. Thus, noise pollution is

considered not only an environmental

nuisance but also a threat to public health.

WHO report

Wallace Clement Sabine(June 13, 1868 – January 10, 1919)

American physicist who founded the field of architectural acoustics

Architectural acoustics

Definition: Reverberation time

Sound pressure level, dB

Time, seconds

60 dB

T60

His formula

where

T=the reverberation time (s)V=the room volume (m3)A=the total equivalent absorption area (m2 sabin)

where

=A

VT 16.0

=TV

A 16.0or

The equivalent absorption area A for a surface with area S m2

is equal to α x S where α is the absorption coefficient for the surface

The broadband reverberation time, which considers all frequencies simultaneously, was 75 seconds – the figure certified as a world record by Guinness.

The oil-storage complex at Inchindown, near Invergordon in Scotland, was built during the Second World War

https://soundcloud.com/tags/sonic%20wonderland

The oil-storage complex at Inchindown

Standards and regulations

Absorption coefficient at normal incidence

AbsorberIncident sound energy

Reflected sound energy

Absorbed sound energy

�� = ��

��

Absorption coefficient as a function of frequency

20 mm glass wool absorber directly mounted in front of a hard surface (concrete)

Glass wool

Open and closed structures

Closed cell Open cell Simple model of porous absorber

Microscopic structure

Sabine formula

where

T=the reverberation time (s)V=the room volume (m3)A=the total equivalent absorption area (m2 sabin)

where

=A

VT 16.0

=TV

A 16.0or

The equivalent absorption area A for a surface with area S m2

is equal to α x S where α is the absorption coefficient for the surface

On the use of practical absorption coefficients

S,

VA=equivalent absorption area, m2 sabine

V= room volyme, m3

T= reverberation time, s

absorption coefficient

α = ∆A/S

Measurement of absorption coefficients according to EN ISO 354

α

withoutTV

withTVAAA

withoutwith⋅−⋅=−=∆ 16.016.0

FHU - Acoustic specification

S

A=α

Equivalent absorption area (ISO 354)

A (m2)

Absorption factor (ISO 354)

S ?

Absorbent ceiling FHU – free hanging unit

V

Reverberation chamber

)11(16.0withoutTwithT

VA −=

AFHU =A/6

Free hanging units “Solo”

Typical classroom

Effect of furniture

absorption

scattering

Reverberation decay in rooms with suspended absorbent ceiling

T20

Increased diffusivity

No boxes

Boxes on the wall

Sabine

Scattering – why is it important?

Glass wool

Absorption and scattering

� + 1 − � ∙ 1 − � + 1 − � ∙ � = 1

absorbed specularly reflected diffusely reflected

Simulation of sound fields

Lambert’s law:

# $ = # 0 cos($)

Acoustical radiosityThe image source method

PARISM – simulation tool for ordinary roomsIndustrial PhD project together with DTU

Forskning

Auralisation with loudspeaker array using higher order ambisonics

Forskning

Activity based acoustic design – a method to approach room acoustic design

Several room

acoustic parameters

are needed for a

relevant

characterization of

room acoustic

conditions

Assessment of sound in rooms

Sound source

Physical regionPhysiological and psychological region Room

Sensation• Sound strength• Clarity• Sharpness• …

Preference

Assessment of sound in rooms

Room types

Reverberant room

(Sabine room)

Open-plan spaces

Room with absorbent

ceiling

Room acoustic quality aspects• Reverberation• Speech clarity• Auditory strength• Spatial decay

Efterklang

• Relaterar till hur snabbt ljudenergin försvinner i ett rum

Lång efterklang

Kort efterklang

Parameters for performance spaces ISO 3382-1

Subjective quality Objective measure

Clarity Clarity index (C80)

Reverberance Early decay time (EDT))

Intimacy Sound strength (level)

Source broadening Early lateral fraction and

strength

Loudness Sound strength and source-

receiver distance

M. Barron, The development of concert hall design – A 111 year experience, Proce

edings of the Institute of Acoustics, Vol. 28. Pt. 1. 2006

Ämnesområdet: Rumsakustik för arbetsmiljöer

ISO 3382-2: Reverberationtime in ordinary rooms

ISO 3382-3: Open plan offices(T20 not included)

Schools

Offices

Hospitals


Room acoustic quality aspects and parameters

Ordinary rooms:• Reverberation: T20 (s), ISO 3382-2• Speech clarity: C50 (dB), ISO 3382-1• Auditory strength: G (dB), ISO 3382-1

Open plan spaces:• Spatial decay: according to ISO 3382-3


Useful reflections

Detrimental reflections

)end)Energy(50

50ms)Energy(0log(10C50 −

−×= , dB

Definition of room acoustic measures: Speech Clarity C50 (dB)

Room acoustic measures: Sound strength G (dB)

G = LpRoom – Lp10m =Lp – Lw + 31 dB (omni-directional sound source)

10 m

G=70 dB - 60 dB= 10 dB

Calibrated Sound Power Source

Subjective listener aspect

Room acoustic quantity

Just noticeable difference

Subjective level of sound

Sound Strength G in dB 1 dB

Perceived reverberance

Reverberation time T20 in seconds

5%

Perceived clarity of sound

Speech Clarity C50 in dB 1 dB

Just noticeable difference of room acoustic quantities according to ISO 3382-1

Microphone

Loudspeaker

Reverberation time, T20

Speech clarity, C50

Sound Strength, G

Impulse response

time, s

Room acoustic measurements

Small meeting rooms

Two similar rooms with different ceiling treatment.

Room 1: Ceiling absorber αw = 1.0

Room 2: Ceiling absorber αw = 0.1

Floor area = 12 m2

Height = 2.7 m

Semantic differential questionnaires

Extremely Very Fairly Partly Fairly Very Extremely

Distinct Indistinct

Pleasant Unpleasant

Dry Reverberant

Best possible

listening

environment

Worst possible

listening

environment

Best possible

speaking

environmen

Worst possible

speaking

environmen

X

Listening test

Measurement results

Measurement results, with wall panels

Ecophon recommendation: Schools

Criteria Parameter* Target values

Speech clarity C 50 (dB) 6 – 8 dB

Sound strength

G (dB) 15 – 17 dB

Reverberation T 20 (s) 0,40 – 0,50 s

* Average 125 to 4000 Hz

The effect of different acoustical treatment

Volume= 150 m3, Floor area=55 m2, ceiling height=2,70 m

• No ceiling treatment, no furniture

• Ceiling treatment, no furniture

• Ceiling treatment, furniture

• Wall panels• Extra low frequency

absorption

Classroom in different configurations

Without furniture and ceiling Without furniture, with ceiling

With furniture and ceiling With furniture, ceiling and wall panels

Without furniture and ceiling

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency (Hz)

Reverberation time T20 (s)

-9,00

-7,00

-5,00

-3,00

-1,00

1,00

3,00

5,00

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz

Speech Clarity C50 dB

0,00

5,00

10,00

15,00

20,00

25,00

30,00

125 250 500 1000 2000 4000

So

un

d s

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

Average absorption coefficient of the room surfaces is 0,05

Practical absorption coefficient of Gedina A

0

0,2

0,4

0,6

0,8

1

1,2

125 250 500 1000 2000 4000

Pra

ctic

al

ab

sorp

tio

n c

oe

ffic

ien

t

Frequency Hz

Gedina A

Without furniture with ceiling

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency (Hz)


-9,00

-7,00

-5,00

-3,00

-1,00

1,00

3,00

5,00

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0,00

5,00

10,00

15,00

20,00

25,00

30,00

125 250 500 1000 2000 4000

So

un

d s

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

Without furniture with ceiling

-9,00

-7,00

-5,00

-3,00

-1,00

1,00

3,00

5,00

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency (Hz)


Calculation according Sabine formula

0,00

5,00

10,00

15,00

20,00

25,00

30,00

125 250 500 1000 2000 4000

So

un

d s

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

With furniture and ceiling

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency (Hz)


-2

-1

0

1

2

3

4

5

125 250 500 1000 2000 4000Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0

2

4

6

8

10

12

14

16

18

125 250 500 1000 2000 4000

So

un

d s

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

With furniture and ceiling

-2

-1

0

1

2

3

4

5

125 250 500 1000 2000 4000Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0

2

4

6

8

10

12

14

16

18

125 250 500 1000 2000 4000

So

un

d s

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency (Hz)


The effect of wall panels

0,00

0,20

0,40

0,60

0,80

1,00

1,20

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency Hz


0

1

2

3

4

5

6

7

8

9

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0

2

4

6

8

10

12

14

16

125 250 500 1000 2000 4000

So

un

d S

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

Ecophon Gedina A with Extra Bass

The effect of extra low frequency absorptionWith 50% Ecophon Extra Bass

0,00

0,20

0,40

0,60

0,80

1,00

1,20

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency Hz


0

1

2

3

4

5

6

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0

2

4

6

8

10

12

14

16

125 250 500 1000 2000 4000

So

un

d S

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

Wall panels and Ecophon Extra BassWith 50% Ecophon Extra Bass

0,00

0,20

0,40

0,60

0,80

1,00

1,20

125 250 500 1000 2000 4000

Re

ve

rbe

rati

on

tim

e (

s)

Frequency Hz


0

1

2

3

4

5

6

7

8

9

125 250 500 1000 2000 4000

Sp

ee

ch C

lari

ty C

50

dB

Frequency Hz


0

2

4

6

8

10

12

14

16

125 250 500 1000 2000 4000

So

un

d S

tre

ng

th G

dB

Frequency Hz

Sound Strength G dB

Acoustic design and architecture

Directional diffusion

© E

cophon Group Effects of directional diffusion in a room with

absorbing ceilingInternship: Tim Näsling 2017

40 different configurations

© E

cophon Group

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

10,0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80

0,90

1,00

C5

0(d

B)

Diffusor coverage

T2

0(d

B)

Effect of diffusion direction and amount on room acoustic

parameters. Dotted line = Just Noticable Difference.

Dc - T20 (s) Dc - C50 (dB)

Content• ISO 3382-3• Sound propagation in open-plan offices• Room acoustic parameters for open-plan offices• Radius of comfort• The effect of ceilings, screens and wall panels in open-plan offices• Conclusions

Acoustic measurements in open-plan officesISO 3382-3

Open-plan Offices

ISO 3382-3Acoustics measurements in open-plan offices.

ISO 3382-1: Performance spaces

ISO 3382-2: Reverberation time in ordinary room

Sound propagation in reverberant rooms

Reverberation time vs. distance

2 4 6 8 10 12 140

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Distance from sound source, m

Rev

erbe

ratio

n tim

e T 20

, s

1 2 3 4 5 6 7 8 910 15 20 30-45

-40

-35

-30

-25

-20

-15

-10

-5

Distance from sound source (m)

Lp -

Lw

(dB

)

Dicentia before refurbishment, path AFree fieldDicentia after refurbishment, path ADicentia before refurbishment, path BDicentia after refurbishment, path BVattenfall helpdesk before refurbishment, path AVattenfall helpdesk after refurbishment, path AVattenfall helpdesk before refurbishment, path BVattenfall helpdesk after refurbishment, path BVattenfall economic department, path BVattenfall economic department, path AStatoil, path AStatoil, path BRIL

Sound propagation in open plan offices

Sound propagation in an open plan office

-10

-20

-30

-40

-50

-601.0 10 100

Sound propagation in open plan spaces

Rel

ativ

e so

und

pres

sure

leve

l, dB

Distance, meter

--- With furniture

--- Without furniture

6 dB/Doubling6 dB/Doubling

-10

-20

-30

-40

-50

-601.0 10 100

Sound propagation in open plan spaces

Rel

ativ

e so

und

pres

sure

leve

l, dB

Distance, meter

Increased absorption

6 dB/Doubling6 dB/Doubling

Room acoustic parameters for open-plan offices

• Spatial decay rate of A-weighted SPL of speech D2,S

• A-weighted SPL of speech at 4 meter, Lp,A,S,4m

• Distraction distance, rD (STI)• Average A-weighted background noise level, Lp,A

The effect of STI on the performance of cognitively demanding tasks

y minimum change in task performance

x speech transmission index

STI

The determination of D2,S, Lp,A,S,4m and rd

Evaluation of office acoustics:

Single value - Radius of comfort rc (m)

• Definition: the distance for a 10 dB decrease of normal “office” speech. Normal speech level in an office is about 58 dB(A) at 1 meter distance.

• rc is calculated from parameters defined in the measurement standard for open-plan offices: ISO 3382-3.

Interpretation:short radius of comfort (rc) means increased privacy

and less disturbance between workplaces

�� = 4 ∙ 10,..(/0,2,3,45678)/:;,3

Distance of comfort rc

D2,S Lp,A,S,4 m

Master Thesis: Room Acoustic Design

Objectives

• Parametrical study of room acoustic parameters (stress test) of Ecophon Acoustic Calculator*

• Control of Ecophon recommendations and adjustments for large spaces

Method

• Setup of parametrical study concerning room dimensions and acoustical treatment

• Using the existing room acoustic calculator for calculations

• Validation with field measurements

Start date: Spring 2019

In collaboration with Ecophon

Supervisor: Emma Arvidsson, Erling Nilsson (Ecophon, LTH)

Examinator: Delphine Bard (LTH)

Contact: [email protected]

[email protected] Erling Nilsson (Ecophon, LTH)

Master Thesis: Characterization of porous materials

Objectives

• Characterization of acoustical and mechanical properties of mineral wool

Method

• Measurements of porous materials in Kundt’s tube.

• Analysis of material properties

• Simulations in the software AlphaCell.

Start date: Spring 2019

In collaboration with Ecophon

Supervisors: Emma Arvidsson, Erling Nilsson (Ecophon, LTH)

Examinator: Delphine Bard (LTH)

Contact: [email protected]

[email protected]

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