Improving Healthcare

Speech Privacy with

Constrained-Layer

Damping

Benjamin M. Shafer, Acoustician

Brandon Tinianov, CTO, LEED AP

Acknowledgements

• Dennis Paoletti | Tracie Ferguson

• Matthew Boersma, The Boldt Company

• Roger Morton, KHS&S

• Gary Mange | Raul Martinez

• The Dilemma: structural steel designs

• Light-gauge vs. heavy-gauge

transmission loss (TL)

• TL to Speech Privacy Class (SPC)

• Common solution: multiple gypsum

layers

• Constrained-Layer Damping (CLD)

Solution

• Conclusions

Outline

The Dilemma: Structural Designs1

Acoustical

Sp

ee

ch

Priva

cy

Higher

Lower

Structural1Aaron Bétit, Veneklasen Associates, “Performance Details of Metal Stud Partitions,” Sound and Vibration Magazine, March 2010, pp. 14–16.

Lt-Gauge vs. Hv-Gauge Example

10

20

30

40

50

60

70

805

0

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel

X / 25-ga. 24OC / X, TL-92-367 (ref. 2)X / 18-ga. 16OC / X, TL10-117

2R.E. Halliwell, T.R.T. Nightingale, A.C.C. Warnock, and J.A. Birta, “Gypsum Board Walls: Transmission Loss Data,” National Research Council, Canada, Internal Report IRC-IR-761, (1998), pg. 87.

SPC ≈ TL(ave) + Ln(ave) + 1,

where

TL(ave) and Ln(ave) are the arithmetic

averages of the 1/3rd octave band

values (160 Hz–5 kHz) of TL and

background noise3

SPC Defined3

3ASTM Subcommittee E33.03, ASTM International, Standard Test Method for Objective Measurement of the Speech Privacy Provided by a Closed Room, ASTM Standard E2638 -10, ASTM International, West Conshohocken, Pennsylvania, (2010).

From TL to Speech Privacy Class

(SPC)1

10

20

30

40

50

60

70

805

0

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel Example

X / 25-ga. 24OC / X, TL-92-367 (ref. 3)X / 18-ga. 16OC / X, TL10-117

TL(ave) + Ln(ave) + 1 = SPC,

Assume Ln(ave) = 24 dB(ref. 4)

2R.E. Halliwell, T.R.T. Nightingale, A.C.C. Warnock, and J.A. Birta, “Gypsum Board Walls: Transmission Loss Data,” National Research Council, Canada, Internal Report IRC-IR-761, (1998), pg. 87.4J.S. Bradley, B.N. Gover, “Selecting Walls for Speech Privacy,” National Research Council, Canada, Internal Report IRC-RR-314, (2011), pg. 6.

Lt-Gauge vs. Hv-Gauge SPC

7871

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel Example

X / 25-ga. 24OC / X X / 18-ga. 16OC / X

Lt-Gauge vs. Hv-Gauge SPC

7871

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel Example

X / 25-ga. 24OC / X X / 18-ga. 16OC / X

STANDARD SPEECH PRIVACY(one or two words occasionally intelligible and frequently audible)3

3ASTM Subcommittee E33.03, ASTM International, Standard Test Method for Objective Measurement of the Speech Privacy Provided by a Closed Room, ASTM Standard E2638 -10, ASTM International, West Conshohocken, Pennsylvania, (2010).

Lt-Gauge vs. Hv-Gauge SPC

7871

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel Example

X / 25-ga. 24OC / X X / 18-ga. 16OC / X

STANDARD SPEECH SECURITY(one or two words very rarely intelligible and occasionally audible)3

3ASTM Subcommittee E33.03, ASTM International, Standard Test Method for Objective Measurement of the Speech Privacy Provided by a Closed Room, ASTM Standard E2638 -10, ASTM International, West Conshohocken, Pennsylvania, (2010).

Lt-Gauge vs. Hv-Gauge SPC

7871

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel Example

X / 25-ga. 24OC / X X / 18-ga. 16OC / X

HIGH SPEECH SECURITY(speech essentially unintelligible and very rarely audible)3

3ASTM Subcommittee E33.03, ASTM International, Standard Test Method for Objective Measurement of the Speech Privacy Provided by a Closed Room, ASTM Standard E2638 -10, ASTM International, West Conshohocken, Pennsylvania, (2010).

Common Solution: Multiple Layers?

Common Solution: Multiple Layers?

10

20

30

40

50

60

70

80

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X, TL10-392

X+X / 16-ga. 16OC / X+X, TL10-391

Lt-Gauge Steel

Reference

67 6960

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X X+X / 16-ga. 16OC / X+X

Common Solution: Multiple Layers?

POOR SPEECH PRIVACY

Lt-Gauge Steel

Reference

Damped Solution: Introduction

Constrained-Layer Damping

(CLD)

Shear loading of the damping layer causes

decreased displacement, converting mechanical

energy (vibration) into heat5

5L. Cremer, M. Heckl, E.E. Ungar, Structure-Borne Sound, 2nd Edition, Springer-Verlag, Berlin, Heidelberg, Germany (1988), pg. 247.

Damped Solution: Introduction

Damped Solution: Theoretical CLD

Loss Factor Comparisons6

6Frank Fahy, Sound and Structural Vibration, Academic Press, San Diego, California, US (1985), pg. 143–164.

Damped Solution: Theoretical CLD

Unbounded Flexible Panel TL6

6Frank Fahy, Sound and Structural Vibration, Academic Press, San Diego, California, US (1985), pg. 143–164.

Damped Solution: CLD one side vs

3-layer Type X

10

20

30

40

50

60

70

80

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X, TL10-392

Dmp / 16-ga. 16OC / X, TL10-393

6772

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X Dmp / 16-ga. 16OC / X

Damped Solution: CLD one side vs

3-layer Type X

Damped Solution: CLD both sides

vs 4-layer Type X

10

20

30

40

50

60

70

80

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X+X, TL10-391

Dmp / 16-ga. 16OC / Dmp, TL10-394

6976

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel

X+X / 16-ga. 16OC / X+X Dmp / 16-ga. 16OC / Dmp

Damped Solution: CLD both sides

vs 4-layer Type X

Optimization: CLD + Stud Width

Damped Solution: CLD one side vs

3-layer Type X

10

20

30

40

50

60

70

80

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

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0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 6” Steel

X+X / 16-ga. 16OC / X, TL10-397

Dmp / 16-ga. 16OC / X, TL10-398

6973

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 6” Steel

X+X / 16-ga. 16OC / X Dmp / 16-ga. 16OC / X

Damped Solution: CLD one side vs

3-layer Type X

Damped Solution: CLD both sides

vs 4-layer Type X

10

20

30

40

50

60

70

80

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 6” Steel

X+X / 16-ga. 16OC / X+X, TL10-396

Dmp / 16-ga. 16OC / Dmp, TL10-399

7279

60

65

70

75

80

85

90

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 6” Steel

X+X / 16-ga. 16OC / X+X Dmp / 16-ga. 16OC / Dmp

Damped Solution: CLD both sides

vs 4-layer Type X

SPC Results Summary

3-5/8” Single Steel 16” OC + 3-1/2” Batt Insulation

Assembly SPC Min SP?

2 layers 5/8” Type X / 5/8” Type X 67 No

Damped / 5/8” Type X 72 No

2 layers 5/8” Type X / 2 layers 5/8” Type X 69 No

Damped / Damped 76 Yes

SPC Results Summary

3-5/8” Single Steel 16” OC + 3-1/2” Batt Insulation

Assembly SPC Min SP?

2 layers 5/8” Type X / 5/8” Type X 67 No

Damped / 5/8” Type X 72 No

2 layers 5/8” Type X / 2 layers 5/8” Type X 69 No

Damped / Damped 76 Yes

6” Single Steel 16” OC + 6” Batt Insulation

Assembly SPC Min SP?

2 layers 5/8” Type X / 5/8” Type X 69 No

Damped / 5/8” Type X 73 No

2 layers 5/8” Type X / 2 layers 5/8” Type X 72 No

Damped / Damped 79 Yes

• Multiple layers of gypsum =

inadequate speech privacy

• Constrained-layer damping (CLD) =

meet/exceed standard speech

privacy

• CLD transmission loss vs. multi-layer

gypsum, broad frequency range

• Increasing stud width from 3-5/8” to 6”

• Further optimization/double-leaf

modeling/field testing

Conclusions

Cost Effectiveness of CLD

San Francisco Hospital Case Study

• Replacing double-layers resulted in 101,339 sqft less gypsum delivered to jobsite

• Reduction of 178 Carpenter Man Days• Reduction of drywall screw inspections

• 6 fewer 30 yd dumpsters to remove scrap

Savings with CLD Panel

Labor & Material Savings $141,775

Reduced IOR Inspections $90,000

Reduced 30YD dumpsters $4,260

Total Cost Savings $236,035

Thank you

Questions?

Conclusions

CLD one side 16” OC vs. 24” OC

10

15

20

25

30

35

40

45

50

55

60

50

63

80

10

0

12

5

16

0

20

0

25

0

31

5

40

0

50

0

63

0

80

0 1k

1.2

5k

1.6

k

2k

2.5

k

3.1

5k

4k

5k

6.3

k

Tran

smis

sio

n L

oss

(d

B)

Frequency (Hz)

Single 3-5/8” Steel

Dmp / 16-ga. 16OC / X, TL10-392

Dmp / 16-ga. 24OC / X, TL10-395

72 73

60

65

70

75

80

Spe

ech

Pri

vacy

Cla

ss (

SPC

)

Single 3-5/8” Steel

Dmp / 16-ga. 16OC / X Dmp / 16-ga. 24OC / X

CLD one side 16” OC vs. 24” OC

STC 48STC 43