This is a presentation that I did on speech privacy of healthcare spaces, regarding the use of damped panels versus multiple layers of drywall. It focused more on the transmission of speech sound than any other type of noise.

1. Improving Healthcare
Speech Privacy with
Constrained-Layer
Damping
Benjamin M. Shafer, Acoustician
Brandon Tinianov, CTO, LEED AP

2. Acknowledgements
• Dennis Paoletti | Tracie Ferguson
• Matthew Boersma, The Boldt Company
• Roger Morton, KHS&S
• Gary Mange | Raul Martinez

3. Outline
• 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

4. Speech Privacy The Dilemma: Structural Designs1
Higher
Lower
Acoustical Structural
1Aaron Bétit, Veneklasen Associates, “Performance Details of Metal Stud Partitions,” Sound and Vibration Magazine, March 2010, pp. 14–16.

5. Lt-Gauge vs. Hv-Gauge Example
Single 3-5/8” Steel
80
X / 25-ga. 24OC / X, TL-92-367 (ref. 2)
70 X / 18-ga. 16OC / X, TL10-117
Transmission Loss (dB)
60
50
40
30
20
10
1.25k
3.15k
1k
2k
4k
5k
63
630
1.6k
2.5k
6.3k
50
80
100
125
160
200
250
315
400
500
800
Frequency (Hz)
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.

6. SPC Defined3
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
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).

7. From TL to Speech Privacy Class
(SPC)1
Single 3-5/8” Steel Example
80
X / 25-ga. 24OC / X, TL-92-367 (ref. 3)
70 X / 18-ga. 16OC / X, TL10-117
Transmission Loss (dB)
60
50
40
30
20 TL(ave) + Ln(ave) + 1 = SPC,
10 Assume Ln(ave) = 24 dB(ref. 4)
1.25k
3.15k
1k
2k
4k
5k
63
1.6k
2.5k
6.3k
50
80
100
125
160
200
250
315
400
500
630
800
Frequency (Hz)
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.

8. Lt-Gauge vs. Hv-Gauge SPC
Single 3-5/8” Steel Example
90
85
Speech Privacy Class (SPC)
80
75
70
78
65 71
60
X / 25-ga. 24OC / X X / 18-ga. 16OC / X

9. Lt-Gauge vs. Hv-Gauge SPC
Single 3-5/8” Steel Example
90
85
Speech Privacy Class (SPC)
STANDARD SPEECH PRIVACY
80 (one or two words occasionally intelligible and frequently audible)3
75
70
78
65 71
60
X / 25-ga. 24OC / X X / 18-ga. 16OC / X
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).

10. Lt-Gauge vs. Hv-Gauge SPC
Single 3-5/8” Steel Example
90
STANDARD SPEECH SECURITY
(one or two words very rarely intelligible and occasionally audible)3
85
Speech Privacy Class (SPC)
80
75
70
78
65 71
60
X / 25-ga. 24OC / X X / 18-ga. 16OC / X
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).

11. Lt-Gauge vs. Hv-Gauge SPC
Single 3-5/8” Steel Example
90 HIGH SPEECH SECURITY
(speech essentially unintelligible and very rarely audible)3
85
Speech Privacy Class (SPC)
80
75
70
78
65 71
60
X / 25-ga. 24OC / X X / 18-ga. 16OC / X
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).

12. Common Solution: Multiple Layers?

13. Common Solution: Multiple Layers?
Single 3-5/8” Steel
80
Lt-Gauge Steel
X+X / 16-ga. 16OC / X, TL10-392 Reference
70 X+X / 16-ga. 16OC / X+X, TL10-391
Transmission Loss (dB)
60
50
40
30
20
10
63
50
80
1k
4k
5k
630
1.25k
2k
1.6k
2.5k
3.15k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

14. Common Solution: Multiple Layers?
Single 3-5/8” Steel
90
Lt-Gauge Steel
Reference
85
Speech Privacy Class (SPC)
80
75
POOR SPEECH PRIVACY
70
65
67 69
60
X+X / 16-ga. 16OC / X X+X / 16-ga. 16OC / X+X

15. 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.

16. Damped Solution: Introduction

17. Damped Solution: Theoretical CLD
Loss Factor Comparisons6
6Frank Fahy, Sound and Structural Vibration, Academic Press, San Diego, California, US (1985), pg. 143–164.

18. Damped Solution: Theoretical CLD
Unbounded Flexible Panel TL6
6Frank Fahy, Sound and Structural Vibration, Academic Press, San Diego, California, US (1985), pg. 143–164.

19. Damped Solution: CLD one side vs
3-layer Type X
Single 3-5/8” Steel
80
X+X / 16-ga. 16OC / X, TL10-392
70 Dmp / 16-ga. 16OC / X, TL10-393
Transmission Loss (dB)
60
50
40
30
20
10
63
50
80
1k
4k
5k
630
1.25k
2k
1.6k
2.5k
3.15k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

20. Damped Solution: CLD one side vs
3-layer Type X
Single 3-5/8” Steel
90
85
Speech Privacy Class (SPC)
80
75
70
72
67
65
60
X+X / 16-ga. 16OC / X Dmp / 16-ga. 16OC / X

21. Damped Solution: CLD both sides
vs 4-layer Type X
Single 3-5/8” Steel
80
X+X / 16-ga. 16OC / X+X, TL10-391
70 Dmp / 16-ga. 16OC / Dmp, TL10-394
Transmission Loss (dB)
60
50
40
30
20
10
63
50
80
1k
4k
5k
630
1.25k
2k
1.6k
2.5k
3.15k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

22. Damped Solution: CLD both sides
vs 4-layer Type X
Single 3-5/8” Steel
90
85
Speech Privacy Class (SPC)
80
75
70
76
65
69
60
X+X / 16-ga. 16OC / X+X Dmp / 16-ga. 16OC / Dmp

23. Optimization: CLD + Stud Width

24. Damped Solution: CLD one side vs
3-layer Type X
Single 6” Steel
80
X+X / 16-ga. 16OC / X, TL10-397
70 Dmp / 16-ga. 16OC / X, TL10-398
Transmission Loss (dB)
60
50
40
30
20
10
63
50
80
1k
4k
5k
630
1.25k
2k
1.6k
2.5k
3.15k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

25. Damped Solution: CLD one side vs
3-layer Type X
Single 6” Steel
90
85
Speech Privacy Class (SPC)
80
75
70
73
65
69
60
X+X / 16-ga. 16OC / X Dmp / 16-ga. 16OC / X

26. Damped Solution: CLD both sides
vs 4-layer Type X
Single 6” Steel
80
X+X / 16-ga. 16OC / X+X, TL10-396
70 Dmp / 16-ga. 16OC / Dmp, TL10-399
Transmission Loss (dB)
60
50
40
30
20
10
63
50
80
1k
4k
5k
630
1.25k
2k
1.6k
2.5k
3.15k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

27. Damped Solution: CLD both sides
vs 4-layer Type X
Single 6” Steel
90
85
Speech Privacy Class (SPC)
80
75
70
79
65 72
60
X+X / 16-ga. 16OC / X+X Dmp / 16-ga. 16OC / Dmp

28. 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

29. 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

30. Conclusions
• 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

31. 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

32. Conclusions
Thank you
Questions?

33. CLD one side 16” OC vs. 24” OC
Single 3-5/8” Steel
60
Dmp / 16-ga. 16OC / X, TL10-392
55
Dmp / 16-ga. 24OC / X, TL10-395
50
Transmission Loss (dB)
45
40
35
30
25
20
15
10
63
50
80
1k
2k
5k
630
1.25k
1.6k
2.5k
3.15k
4k
6.3k
100
125
160
200
250
315
400
500
800
Frequency (Hz)

34. CLD one side 16” OC vs. 24” OC
Single 3-5/8” Steel
80
STC 43 STC 48
Speech Privacy Class (SPC)
75
70
65 72 73
60
Dmp / 16-ga. 16OC / X Dmp / 16-ga. 24OC / X