hubbard 1982 noise induced house vibrations airports

8/12/2019 Hubbard 1982 Noise Induced House Vibrations Airports

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Noise Induced House Vibrat ionsand Human Percept ion

Harvey H. Hubbard member INCE t summarizes noise induced house responsesincluding frequencies mode shapes acceleration levels and outside-to-inside noisereductions. The role of house vibrations in reactions to environmental noise isdefined and some human perception criteria are reviewed.

One aspect of communit y response to noise involves peopleinside houses. Since house structures have many componentswhich are readily excited by noise and which can be coupled,they respond as complex vibrating systems. These dynamicresponses are significant because they affect the environmentof the observers inside the house. The nature of this noiseinduced house excitation problem is illustrated in Fig. 1.

A person inside the house can sense the impingement ofnoise on the external surfaces of the house by means of thefollowing phenomena: noise transmitted throu gh the struc-ture f rom outside to inside see Refs. 1-6); the vibrations ofthe prima ry components of the building such as the floors,walls and windows see Refs. 2,3,7 and 8); the rattling ofobjects such as dishes, ornaments and shelves which are set*Received 28 April 1982; revised 1 uly 1982tThe College of William and Mary, Virginia AssociatedResearch Campus, 12070 Jefferson Avenue, Newport News,Virginia 23606

in motion by the vibration of the primary components seeRefs. 2, 3 and 9); and in the extreme case damage to the secon-dary structure such as plaster and tile an d/ or furnishings seeRef. 7).

The pu rpose of this article is to summarize available dataon house vibration responses due to airborne noise excita-tion and t o define the role of such vibrations in the problemof human perception of environmental noise. The buildingresponse data contained herein, are derived largely from air-craft noise, helicopter noise and sonic boo m flyover tests.The associated findings are believed to apply directly to anysituations for which the airborn e noise component is largecompared to the seismic component. The material of thisarticle was developed initially as an appendix o f Ref. 10, andhas been applied to the co mmun ity noise evaluation of largewind turbine generators. In situations for which seismicexcitation of the house structure can be significant, as forroad and rail traffic, the response data of the present articlemay be inadequate.

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I I I I I I I I I ~ V l l I I I I I I I I

/ - N O I S E T R A N S M I S S I O N - - ~OUTSIDE INSIDEVIBRATIONEXCITATION ~ -~ IN DU CE D NO ISE /-~ - -OBSERVATINS NOISE NOISE VIBRATION

DAMAGEFigure 1--N atur e of noise induced house structure responses 3

BEDROOMCEILING~--FA MILY ROOM~ ~ . _ ~ / FLOOR - - // '~ F A M IL Y~ ~ . ~ I ROOM~ ~ W A L L

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= 6 . o z = . O TEXCITATION PO IN T ~ I ~--r-4~- L E ' Y ' - ~ R T H

Figure 2--Exam ple frequencies and mode shapes fo r a one-storyhouse excited by a mechanical shaker forc e input-35.6 newtons 2

V i b r a t i o n s o f H o u s e M a i nS t r u c t u r e omp on e n t sD a t a o n t h e v i b r a t i o n r e s p o n s e s o f h o u s e s i s d e r i v e d f r o m

s e v e r al d i f fe r e n t s o u r c e s . S o m e m e a s u r e m e n t s a r e a v a i l a b lef r o m b u i ld i n g s i n s t r u m e n t e d w i t h a c c e l e r o m e t e rs , d e f l e c t io ng a u g e s a n d / o r s t r a i n g a u g e s o n w a l l s , f l o o r s , c e i l i n g s a n dw i n d o w s t o r e c o r d t r a n s i e n t r e s p o n s e s d u e t o f l y o v e rs o f s u b -s o n i c je t a n d p r o p e l l e r a i r c r a ft a n d h e l i c o p te r s ; a n d t h e s o n i cb o o m s o f s u p e r s o n i c a i rc r af t. 2 .' - '~ I n a d d i t i o n , a n u m b e r o fe x p e r i m e n t s h a v e b e e n c o n d u c t e d i n w h i c h m e c h a n i c a ls h a k e r s h a v e b e e n u s e d t o e x c i t e a n d m e a s u r e t h e r e s p o n s e so f h o u s e s a n d h o u s e c o m p o n e n t s . 2,8 R e s u l ts o f th e f l y o v e ra n d m e c h a n i c a l v i b r a t i o n t e s t s a r e c o n s i s t e n t a n d t e n d t oc h a r a c t e r i z e t h e m a n n e r i n w h i c h h o u s e s t r u c t u r e s r e s p o n dt o a c o u s t i c l o a d i n g s .Frequencies and M ode Shapes E x a m p l e m o d e s h a p e s a n df r e q u e n c i e s f o r a o n e - s t o r y t e s t h o u s e a r e g i v e n i n F i g s . 2a n d 3 . T h e d a t a o f F ig . 2 w e r e o b t a i n e d b y m e a n s o f a f r e -q u e n c y s w e e p f o r a c o n s t a n t i n p u t v i b r a t o r y f o r c e a n d a ta g i v e n p o i n t o f e x c i t a t i o n o n t h e n o r t h w a l l o f b e d r o o mn u m b e r 1 ( s e e i n s e r t s k e t c h ) . T h e e x c i t e d w a l l h a d a f u n -d a m e n t a l r e s o n a n c e a t 1 6 .6 H z . T h e o t h e r w a l l o f th e r o o ma n d i ts f l o o r h a d r e s o n a n c e s a t 2 1 . 4 a n d 2 6 H z r e s p e c t i v e ly .D a t a f o r a n u m b e r o f d i f f e r e n t h o u s e s t ru c t u r e s in d i c a t e f re -q u e n c y v a lu e s f r o m a b o u t 1 2 t o 3 0 H z . T h e a b o v e r e s u lt sa r e r e p r e s e n t a t i v e o f t y p i c a l h o u s e s t r u c t u r e r e s p o n s e s i n t h ef ir s t r e s o n a n c e o r o i l c a n n i n g m o d e s o f th e t y p e i l lu s t ra t e di n Fi g . 2 . N o t e t h a t t h e r e i s e v i d e n c e o f s tr u c t u r a l a n d / o ra i r c a v i t y c o u p l i n g . I t c a n b e s e e n t h a t p r e f e r r e d p h a s e r e l a-t i o n s h i p s e x is t as a r e s u l t o f t h e m a n n e r i n w h i c h t h e f l o o ra n d w a l l s t r u c t u r e s a r e a r r a n g e d .

H i g h e r o r d e r m o d e s m a y , i n s o m e c a s e s , b e e x c i t e d f o rp r e f e r r e d l o a d in g s o r f o r m o r e c o m p l e x s t r u c t u ra l c o n f i g u r a -t i o n s . E x a m p l e s o f s u c h h i g h e r o r d e r m o d e s a r e s h o w n i nF i g . 3 , w h i c h r e l a t e s t o o n e o f t h e t e s t s t r u c t u r e s o f R e f . 2 .D a s h e d l in e s a r e i n c l u d e d t o i n d i c a t e e x p e r i m e n t a l l y d e t e r-m i n e d n o d e l i n es . N o t e t h a t t h e n u m b e r s o f n o d e li n es a n dt h e i r s p ac i n g s d i f f e r f o r t h e t h r e e e x a m p l e r e s o n a n t f r e q u e n -c i es . F o r i n s t a n c e , F i g . 3 a s h o w s a m o d a l p a t t e r n f o r w h i c h

( ' 'T' ' ' '~- W ND w PLAQUES

(a) f =27Hz; m =4, n = (b) f =48Hz, m =8, n -- 2 '---4

(c) f=72H z; m= 8, nF ig u re 3 E xa m p le h ig h er m o d e resp o n ses o f a h o u se w a l l h a v in gdoor and window openings 2t h e n u m b e r o f v e r t i c a l n o d e l in e s is 4 (m = 4 , c o u n t i n g t h ee n d l in e s ) a n d t h e n u m b e r o f h o r i z o n t a l n o d e l i n e s i s 2 ( n = 2 ,c o u n t i n g t o p a n d b o t t o m l in e s) . U n e v e n s p a c in g s o f t h e n o d el i n e s f o r t h e h i g h e r r e s o n a n t f r e q u e n c i e s c a n r e s u l t f r o mg e o m e t r i c d is s y m m e t r y d u e t o w i n d o w a n d d o o r c u t o u t s.

B u i l d in g s t r u c tu r e s a r e c h a r a c t e ri z e d b y n o n h o m o g e n e o u se l e m e n t s . W a i l s , f l o o r s a n d c e i l in g s a re b u i l t - u p f r o m a n a r r a yo f e v e n l y s p a c e d b e a m s w i t h s h e a t h in g o n o n e o r b o t h s id e s .T h e s h e a t h i n g i s t y p i c a l ly a t t a c h e d t o t h e b e a m s a t d i s c r e t ep o i n t s b y m e a n s o f n a i ls . T h e r e s u lt in g s t r u c t u r e o f b e a m sa n d p a n e l s t en d s t o r e s p o n d a s d y n a m i c a l l y c o u p l e d e le m e n t sb u t t h i s b e h a v i o r i s m u c h d i f f e r e n t a t lo w f r e q u e n c i e s t h a na t h i g h f r e q u e n c i e s , s A t l o w f r e q u e n c i e s ( b e l o w 1 0 0 H z ) t h er e s p o n s e i s d o m i n a t e d b y t h e b e h a v i o r o f t h e b e a m s , a s s u g -g e s t e d b y t h e m o d e s h a p e s o f F i g . 2 , a n d t h e s h e a t h i n g p a n e l sp l a y o n l y a m i n o r r o l e . O n t h e o t h e r h a n d , h i g h e r o r d e rm o d a l r e s p on s e s ( a b o v e 30 0 H z ) te n d t o b e d o m i n a t e d b yt h e s h e a t h i n g p a n e l s , d u e t o t h e i r s h o r t e r s p a n s . A t i n -t e r m e d i a t e f r e q u e n c i e s ( 10 0 to 3 0 0 H z ) t h e p a n e l s b e h a v e a si f t h e y w e r e s i m p l y s u p p o r t e d , w h i l e f o r th e h i g h e r f r e q u e n -

50 NOISE CONTROL ENGINEERING JOURNA L/Sep lembe r Oclob er 1982


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c ie s the pane l s behave a s though the i r edges were f ixed /Exper i en ce has shown tha t h ouse s t ruc tures re spo nd in a

l inea r mann er to fo rced exc i t a t ion . 2 For cases where the ac -ce le ra t ions have been measured for a fo rced exc i t a t ion a t ag iven frequency the acceleration amplitudes a re a d i rec tl inea r func t ion of the input fo rce . L ikewise , t he measuredacce le ra t ions inc rease a s a func t ion of f r eque ncy for a g iveninput fo rce , and they gene ra l ly occur abou t a s t ra igh t l i nehaving a pos i t ive slope of 5 dB pe r oc tave up to f requ enc iesof about 1000 Hz , t he l imi t o f measurement s .Win dows va ry in s ize , f rom the p l a t e g la s s type which canb e s e ve r a l m e tr e s i n d i m e n s i o n t o c o n v e n t i o n a l d o u b l e h u n gdes igns hav ing m uch sma l l e r s ash e l ement s . A l l w indows a res imilar in that the m ajo r e lem ent(s ) is a re la t ively thin glasspla te s imply supported a long i ts edges . A pla te glass tes tspec imen of Ref . 8 had n a tura l r e sonances of 9 , 18, 48 and70 Hz for d imen s ions of 1 .22 m by 1 .84 m. Sm al l e r s a sh win-d o w s o f c o n v e n t i o n a l h o u s e s a r e n o t e d t o h a v e r e s o n a n tre sponses in the range of s evera l hundred Her t z . T hus , t her a n g e o f r e s p o n s e f r e q u e n c i e s f o r w i n d o w c o m p o n e n t s o fhouses i s cons i s t en t w i th those for o the r s t ruc tura l com-p o n e n t s . E v i d e n c e o f w i n d o w m o t i o n m a y b e o b s e r v e d b ys igh t , by fee l ing , o r by the ra t t l i ng of loose e l ement s .Acceleration L e v e ls . A l a rg e n u m b e r o f m e a s u r e m e n t s a r eava i l ab le fo r t he no i s e induced acce le ra t ion l evel s in hou ses t ruc tures (acce le ra t ion l evel = 20 log10 (acce le ra t io n ,g / 1 0 9 ) . T h e s e d a t a h a v e c o m e f r o m a w id e r a n g e o f e x p o s u rec o n d i t i o n s a n d r a t h e r d e t ai l ed m e a s u r e m e n t s w e r e o b t a i n e dfor a num ber o f d i f fe ren t house s t ruc tures , ~ - 5 and f rom u n-publ i shed da ta b y N . D . Ke l l ey and by R. D eLo ach , K . P .Sheph erd and E . F . Danie l s . T he above s tud ies re l a t e to theprob lem o f com mu ni ty re sponse to subsonic a i rc ra f t , supe r -son ic a i rc ra f t and he l i cop te rs ; and spec i f ica l ly p rov id e da tare l a t ive to house v ibra t ions an d pos s ib l e damage . Acce le ra -t ions of the va r ious bu i ld ing compo nent s , such a s w indows ,wa i l s and f loors , a re ava i l ab le and exam ple va lues a re g ivenin F igs . 4 , 5 and 6 . In each case the measu red acce le ra t ionsa re p lo t t ed a s a func t ion of the peak sound pres sure l eve l sm e a s u r e d o u t s i d e o f t h e h o u s e .

Wails Data for con vent ion a l wa l l (5 cm by 10 cm s tuds ,doubly shea thed) acce le ra t ion re sponses a re p resen ted in F ig .4 f o r h o u s e s e x p o s e d t o n o i s e f r o m c o m m e r c i a l a n d m i l i ta r yje t a i rc ra f t , he l i cop te rs and prope l l e r a i rc ra f t , and son icb o o m s T h e l a rg e a m o u n t o f d a t a f o r a i r c r a ft a n d h e l ic o p t e rn o i s e a r e e n c o m p a s s e d b y t h e l o w e r h a t c h e d a r e a a n d t h eava i l ab le son ic boo m re l a t ed da ta f i t w i th in the upper c ros sha tched a rea . Th ese da ta , which a re a s soc ia ted wi th a w ideva r i e ty of input spec t ra , s eem to co r re l a t e s a t i s fac tor i ly onthe bas i s o f peak sound pres sure l eve l . I t can be s een tha tthe acce le ra t ion re sponses inc rease gene ra l ly a s the no i s elevels increase and seem to fol low a s t ra ight l ine re la t ion-s h i p b a s e d o n t h e a s s u m p t i o n o f l i n e a r b e h a v i o r o f t h es t ruc ture .

Floors. Simi la r re su l t s a re p resen ted in F ig . 5 fo r housef loor ve r t i ca l acce le ra t ion re sponses . Note tha t a l imi t eda m o u n t o f w i n d t u r b i n e d a t a a r e a l s o i n c l u d e d f r o m R e f .

ACCELERATIONLEVEL, dBre i0 llg--PROJECTED FOR LINEAR RESPONSE1.0 - 120 -.~AIRCRAFT AND HE LI CO PT ER ~N OI SEREF 12-15)SON,CBOOMS ~REF.12 N0a31ACCELERATION 01 ] 100

grms Ol 80 ~

.001 - 60 ~ ~ ~

0001 40 I [ I I60 80 100 120PE KSOUND PRESSURELEVEL, OB 140Figure 4--Measured house wall acceleration responses due to noiseexcitation

A C C E L E R A T I O N

1 . 0

0 IACCELERATION

grms 01 -

LEVEL dBre 1.0 pg120

100

80

.001 - 60

.0001 I dO

PROJECTED0 AIRCRAFTNOISE (REF 12-14)SONIC BOOMS REF. 12 AND 13)~WIND TURBINEREF. 16)

o~ o {~ o

]60 80 I0 0 120 140PEAK SOUND PRESSURE LEVEL dB

Figure 5--Measured house loor vertical acceleration responses dueto noise excitation

i o

0.1 ~-ACCELERAT ON,

grins .01 -

. 001

.0001

ACCELERATIONLEVEL, dBre i0 pg120 r

100-

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6O

40I60

PROJECTED~ AIRCRAFTAND HELICOPTERNOISE (REF.14AND 1.5) /:~ WIND TURBINE KELLEY/

I I I ]80 100 120 140PEAK SOUND PRESSURELEVEL, dBFigure 6 Measu red house windo w acceleration responses due tonoise excitation16. A l l o f t he o the r d a ta sho wn a re fo r the s ame t e s t s t ruc -tu res a s in Fig . 4 , and apply d i rec t ly to the groun d f lo or on ly .F loor acce le rat ions s eem to fo l low genera l ly a l i nea r re sponsere l a t ionsh ip , a s d id the wa l l r e sponse da ta . The s ca t t e r i s ,however , co ns ide rab ly grea te r t han for the wa ll da t a and the

V o l u m e 1 9 / N u m b e r 2 5 1


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re sponses a re abo ut 10 dB lower in l evel fo r a g iven no i s el evel i nput . Fo r comp arab le input s , t he a s soc ia t ed hor i zon-t a l acce le ra t ion va lues a re no ted in Refs . 12 th rou gh 14 tohe abo ut equ a l t o , o r a re s l igh t ly g rea te r t han , t he ve r t i ca lvalues given in the f igure .

W i n d o w s . Measured acce le ra t ion re sponses fo r s eve ra lconvent iona l double hung windows a re shown in Fig . 6 . Win-dow sash wid th and he igh t d imens ions a re about 1 m andglas s th icknes s i s abo ut 3 mm . Go od cor re l a t io n is seen forwide ly d i f fe ren t a i rc ra f t , he l i cop te r and wind tu rb ine no i s ei n p u t s , a n d t h e t r e n d o f th e d a t a i n d i c a t e s l i n e a rre sp on ses ; ~4-~6and unp ubl i shed work b y N . D . Ke l l ey, and b yR. DeL oach , K . P . Sh epherd and E . F . Danie ls . For a g iveninput l eve l t he w indow responses a re no ted to be abo ut 10dB h ighe r in l eve l t han the a s soc ia t ed wa l l r e sponses .Damage Experience Very l it t le i f any dam age to e l ement sof the s t ruc ture i s expec ted except a t ex t reme va lues o f theinput no i s e leve l. Exper i ence for b l a s ting , exp los ions and fors o n i c b o o m s s u g g e s t t h a t d a m a g e t o h o u s e s m a y o c c u r a tpeak acce le ra t ion va lues be tween a bou t 0 .3 and 3 .0 g in thef reque ncy range o f 10 to 100 Hz re spec t ive ly . 7 I t can be s eentha t t he mea sured l eve l s o f wa l l , f l oor and w indow acce le ra -t ions which a re c i t ed for a i rc ra f t , he l i cop te r , and wind tu r -b ine no i s e a re gene ra l ly lower than 0 .3 g and hence no dam agei s expec ted . Sonic bo om exc i t a t ion which i s a s soc ia t ed wi tht h e e x t r e m e v a lu e s o f i n p u t p r e s s u r e h a s b e e n b l a m e d f o rsome inc ip ien t damage to l i gh t s t ruc tura l e l ement s such a swind ows, plas ter and t i le surfaces , e tc . 7,

Vibrations of ccessoriesW a l l o r f l o o r v i b r a t io n s o f t h e t y p e s d e sc r i b e d a b o v e c a n

give r i s e to the v ibra t ion of wa l l o r f loor mounted ob jec t ssuch a s p i c tures , mi r rors , p l aqu es , l amps , e t c . Such ob jec t sa re usua l ly in con tac t w i th the l a rge r sur face a t on e or mo red i s c re t e po in t s o r a long a boundary l ine , and a re pu t i n tomo t ion because of the v ibra tory mot ions of the sur face . Suchexc i t a t ion of ob jec t s re su lt s i n h igh f requen cy impac t sound s ,h i g h f r e q u e n c y v i b r a t i o n s o r s o m e a s s o c i a t e d o p t i c a lp h e n o m e n a w h i c h s e r v e t o i d e n t i f y th e e v e n t a n d b y s o d o -i n g c a us e a n n o y a n c e o f n e a r b y o b s e r v e r s. T h i s i s a n e x a m -ple o f nonl inea r v ib ra t ion re sponses , fo r which the subaudi -b le f requen cy exc i t a t ion of a wa l l , fo r i ns t ance , can causea u d i b l e f r e q u e n c y r a n g e r e s p o n s es i n a w a l l m o u n t e d o b j e c tsuch a s a p i c ture , z : : The ra t t l i ng of such accessor i e s can bea f a c t o r i n a n n o y a n c e .

The da ta o f F ig . 7 a re inc luded to ind ica te the range ofacce le ra t ion re sponses expec ted f r om v ibra t ing acces sor ie s .Two d i f fe ren t c r i t e r i a l i nes a re inc luded f rom Ref . 9 . Botha re shown as be ing hor i z onta l because no s ign i f i can t e f fec t sof f req uency were iden t i fi ed in any of the expe r imenta l da t a .The top l ine i s d raw n a t 1 .0 g and i s t he pred ic t ion for ra t t l -ing in the case of normal con tac t , a s fo r an ob jec t re s t ingon a hor i zo nta l v ibra t ing sur face such a s the f loor . Th e ha t -c h e d a r e a r e p r e s en t s t h e r a n g e o f c o m p a r a b l e e x p e r i m e n t a l

1.0

WALL OR FLOORACCELERAT ONSgpeak 0.1

.01

PREDICTION FORWALL MOUNTEDAT 3 ANGLE-~

3 lO 30 100FREQUENCY Hz 300 1000

Figure 7 Cri ter ia fo r the ratt l ing of wall and f loo r mo unted objects due to vibratory excitationda ta and suggest s t ha t i n p rac t i ca l cases some ra t t l i ng mightoccur a t acce le ra t ion l eve ls le s s than the theore t i ca l va lue of1 .0 g. Such lower acc e le ra t ion va lues a re usua l ly a s soc ia t edwi th sma l l con tac t a reas and pr obab ly re su l t f rom loca l sur-face imper fec t ions and misa l ignment s f rom the ve r t i ca l .

For cases where ob jec t s a re suspended in pend ulum fash ionf ro m the wa l l t he lower c r i t e r i a li ne might app ly . I t shouldapply theore t i ca l ly to s i tua t ions wh ere the hang angle (anglebe tween wa l l and hanging f l a t ob jec t ) is about 3 . The c ros sha tch ing represen t s the range of da ta ava i l ab le fo r a num berof ob jec t s such a s p l aques , p i c tures and mi r rors , f rom houses i tua t ions and for a s t eel bal l i n l abora t ory t e s t s . The s ca t t e rof measu red re su l t s sugges t s t ha t sma l l va r i a t ions in the wa l lgeo met r y or tha t o f t he suspended ob jec t can be s ign i f ican t .By impl i ca t ion , ob jec t s t ha t hang by sma l l e r hang angles a resuscep t ib l e to ra t t l e a t l ower acce le ra t ion l eve l s .

Vibration Perception CriteriaO n e o f t h e c o m m o n w a y s b y w h i c h a p e r s o n m a y s e n s e

the no i s e induced exc i t a t ion of a house is t h rou gh s t ruc tura lv ibra t ions . Thi s mo de o f obse rva t io n i s pa r t i cu la r ly s ign i fi -can t a t f requenc ies be low the th reshold of normal hea r ing ,or in the low f re quen cy range w here the ea r i s l es s s ens i tive .W h o l e B o d y P e r c e p t i o n . T h e r e a r e n o s t a n d a r d s a v a i la b l ef o r t h e t h r e s h o l d o f p e r c e p t i o n o f v i b r a t i o n b y o c c u p a n t sof bu i ld ings . Guide l ines a re ava i l ab le , however , fo r i n t e r imuse . ,,_20 Toge the r they cov er the f reque ncy rang e 0 .063 to 80H z . T h e a p p r o p r i a t e p e r c e p t i o n d a t a f r o m e a c h o f t h e a b o v ed o c u m e n t s a r e r e p r o d u c e d i n F ig . 8 a n d a r e r e p r e s e n t e d b ythe compos i t e heavy l ine curve . Thi s curve represen t s thec o m b i n e d r e s p o ns e s o f a p e r s o n i n e i th e r th e u p a n d d o w n ,fore and a f t , o r s ideways d i rec t ions whichever i s t he mos ts ens i t ive . Thi s i s be l i eved appropr i a t e fo r t he house v ibra -t ion case because pe rsons m ay be in va r ious pos i t ions wh enexper i enc ing v ibra t ions . Th e ha tched reg ion of F ig . 8 encom-p a ss e s t he p e r c e p t i o n t h r e s h o l d d a t a o b t a i n e d i n a n u m b e rof indep ende nt s tudies . 2 -25 Diff eren t inves t igators , us ing dif-fe ren t measurement t echniques , sub jec t s and sub jec t o r i en-t a t ions , have ob ta ined va lues which ex tend ove r a range of

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ACCELERATIONLEVEL dBre 1 .OIJ g -COMPOSITESO GUIDELINES0;I r- 100 REF. 18 AND 19)RANGEOF DATA REF. 20-25)

ACCELERATION .01 80 ~WIND TURBINE OBSERVATIONS / /grms |

001 60

1 40

20 I I I0.1 1.0 10 100ONE-THIRD OCTAVE BAND CENTER FREQUENCY HzFigure 8 Mo st sensit ive threshold o f percept ion o f v ibratorym o t ion by hum ans

a b o u t a f a c t o r o f 1 0 i n v ib r a t i o n a m p l i t u d e . T h e c o m p o s i t e( re l a t ed) gu ide l ines curve o f F ig . 8 i s j udge d to be the bes trepresen ta t ion of the ava i l ab le whole body (mos t s ens i t iveax i s ) v ibra t ion pe rcep t ion da ta .

Note the two c ros s ha tched reg ions on F ig . 8 f rom the d a taof Ref . 26 . These a re e s t ima ted one - th i rd o c tave band l evel so f v i b r a t i o n s w h i c h w e r e j u d g e d p e r c e p t ib l e i n t w o d i f f e r e n thouse s t ruc tures exc i t ed by wind tu rb in e no i s e . Based on theva lues o f the gu ide lines curve they would be judged marg i -na l ly pe rcep t ib l e and thus s eem to cons t i tu t e a good conf i r -m a t i o n o f t h e o t h e r p e r c e p t i o n t h r e s h o l d d a t a o f F i g . 8 .

Figure 9 indicates the outs ide soun d pressu re levels in givenone- th i rd oc tave bands tha t w i l l cause pe rcep t ib l e v ibra t ionins ide a house s t ruc ture . The to p curve was de r ived d i rec t lyf r o m t h e c o m p o s i t e p e r c e p t i o n d a t a c u r v e o f F i g . 8 a n d t h efloor response d ata of Fig. 5. I t i s thus bel ieved that the sou ndpressure level values indicated are eq ual to o r are ne ar in valueo f t h o s e r e q u i r e d t o c a u s e p e rc e p t i b le f l o o r v i b r a t i o n f o r a no c c u p a n t . T h e c u r v e s l a b el e d w a l l s a n d w i n d o w s a r ei n f e r r e d f r o m t h e d a t a o f F i g. 8 a n d t h e h o u s e e l e m e n t d a t arespec t ive ly of F igs . 4 and 6 . I t i s no t c l ea r ho w the conce pto f w h o l e b o d y p e r c e p t i o n a p p li e s t o t h e w a ll a n d w i n d o wvibra t ions , bu t t he h i e ra rchy of house e l ement re sponses sug-ges t ed in F ig . 9 i s cons i s t en t w i th ava i l ab le measurement sand wi th obse rva t ions . F ro m the f igure i t is poss ib le to de te r -mine the ou t s ide sound pres sure l eve l s suf f i c i en t t o causepe rcep t ib l e v ibra t ions of house s t ruc tura l e l ement s ove r arange of f requenc ies . For ins t ance , i f a house was exposedto the example no i s e spec t rum of the f igure , t he re would pro-bably be pe rce ived v ibra t ions o f the wal l s and windows an dno pe rce ived v ibra t ions of the f loors .Tac t i l e Pe rcep t ion . House bu i ld ing v ibra t ions of wa l l s andwindows may a l so be obse rved by means of t ac t i l e pe rcep-t ion (pe rce ived by touch of the f inge r t i ps ) . The ava i l ab let ac t i le pe rcep t ion da ta fo r pure to ne exc i t a t ion in the f re -quen cy range of in t e res t is shown in F ig . 10. The m os t ex-t ens ive s tudy is repor t ed in Ref . 27 and i s represen ted by theso l id curve . Resu l t s o f a s e ri e s o f more abbrev ia t ed s tud iesf rom Ref . 28 a re represen ted by the ha tched a rea . I t can beseen tha t t he re i s a t r end towa rd lower s ens i t iv ity a s the f re -que ncy increases . Th e sens i t ivi ty to tact i le percept io n is com -parab le to tha t fo r whole bo dy pe rcep t ion ( s ee F ig . 8 ) i n therange of f requences nea r 100 Hz . N ote tha t w indow and wa l l

100

BO

SOUNDPRESSURELEVEL 6dB

40

HOUSE ELEMENTS------._ FLOORS

WALLS

jPERCEIVED VIBRATIONS ~ ~/2 -------

EXAMPLE NOISE SPECTRUM -/

2 t

I I I J0.1 1.0 10 100ONE-THIRDOCTAVEBAND CENTERFREQUENCY. HZ

Figure 9 So un d pressure levels sufficient to cause perceptible vibrations of house structure elements over a range o freque ncies

120

lOOACCELERATIONLEVEL dB 80

re 1.0 l~g60

40

20 0.1

27I I I J1.O lO lO0 1000FREQUENCY Hz

Figure lO Pur e tone thresholds of tactile perceptionvibra t ions may be obse rved by t ac t i le pe rcep t ion a t peak no i s el eve l exc i t a t ions of ab out 90 dB (F ig . 6 ) and 100 dB (F ig.4) respect ively.

H o u s e N o i s e A t t e n u a t i o n s

A n o t h e r p h e n o m e n o n o b s e r v e d b y t h e o c c u p a n t s o f ahouse i s t he no i se t ransmi t t ed to the ins ide spaces f ro m theout s ide . T he ins ide no i s e exposures a re d i f fe ren t f rom thoseon the ou t s ide because of the in f luence of the house s t ruc -tu re a s the no i se is tr ansmi t t ed th rou gh i t . Und er no rmal c i r -cums tances the no i s e l eve l s a re reduced . Da ta showing ex-a m p l e h o u s e n o i s e r e d u c t i o n s a s a f u n c t i o n o f f r e q u e n c y a r eg iven in F ig. 11. The ha tch ed a r ea encomp asses re su lt s ob-t a ined in Refs . 1 th rou gh 6 . Th e no i s e reduc t io n va lues o fthe ord ina te a re the d i f fe rences be tween ins ide and ou t s ideread ings . The mos t obvious re su l t i s t ha t t he no i s e reduc -t ions a re l a rge r a t t he h ighe r f requen c ies . Thi s impl i es tha tthe m easu red spectra ins ide the hou se wi l l have re la t ively lessh i g h f r e q u e n c y c o n t e n t t h a n t h o s e o n t h e o u t s id e .

There a re ve ry few da ta ava i l ab le a t t he low f requenc ies(be low 50 Hz) . In th i s range the wave lengths a re com parab leto the d imens ions o f the rooms a nd the re i s no longer a d i f -fuse sound - f i e ld on the ins ide . 29 Othe r co mpl i ca t ing fac torsa re the ro l e o f s t i f fnes s a t t hese lower f requenc ies and theex i s t ence of a i r l eaks . The ins ide d i s t r ibu t ion of pres sure canb e n o n u n i f o r m b e c a u se o f s t r u c t u r e b o r n e s o u n d , s t a n d i n gw a v e p a t t e rn s , o r g a n p i p e m o d e s a n d c a v i t y re s o n a n c e s d u eto roo m, c loset and hal lway config urat ions . 3o The ant ic ipated

V o l u m e 1 9 / N u m b e r 2 5 3


6/7

- - PROJECTED4 0 , ~ \ \ \ R A N G E O F A V A I L A B L E M E A S U R E M E N T S

No sE 3REDUCTION,

O 2010 ~ ~0 I I i r I

1 .0 10 100 1000 10000FREQUENCY, Hz

Figure 1 I-- Hou se no i se reduc t i o n as a f u n c t i o n o f r e qu e n c y ort h e w i n d ow s cl o s ed c o n d i t i o n\ \ ~ - PURE TONE HEARING THRESHOLD. REF. 32\

I00 \ \

SOUND //NOISES REF. 5PRESSUREEVELB 60 ~ / / / / / / ~ ? / / / / / / ~ / / ~W I N D T U R B I N E HEARIN ~ / / X~ \

40 THRESHOLD,REF. 31i20 l -- __ \ i __11.0 IO 1DO I000

ONE-THIRD OCTAVE BAND CENTERFREQUENCY. HzFigure 12 Rang e o lo w freque ncy inside no ise levels wh ich causeddverse re c t ions by occup n tsl ar ge var ia t ion o f s ound pr e s s ur e l e ve l s f r om one loc a t ionto anothe r a t ve r y low e xc i ta t ion fr e que nc ie s has no t be e ndoc u me n te d for hous e s . T hus , i t i s d i f f ic u l t to c har ac te ri z ethe low fr e que nc y no i s e e nv ir onme nt ins ide o f a hou s e s truc -tur e bas e d on a kn owle dge o f the outs ide no i s e e nv ir onme nt .

L o w F r e q u e n c y N o i s e P e r c e p t i o nThere are fragm entary reports that indicate som e unusual

r e ac t ions to n o i s e a t ve r y low fr e que nc ie s , par t ic u lar ly wh e nsuch n oises are observed ins id e a s tructure or a vehic le.5 Th edata o f F ig . 12 ar e r e pr es entat ive o f s om e o f the do c um e nte dc as e s . A numbe r o f the s e are c i te d whe r e low fr e que nc y no i s efr om indus tr ia l ope r at ions has pr opagate d r e la t ive ly longdistances into residential areas and has resulted in com plain ts.T he hatc he d ar ea o f F ig . 12 e nc om pas s e s the r ange s o f f r e -que nc y and no i s e l eve l whic h ar e be l i e ve d to have c aus e d thec ompla ints . I n a l l c as e s the l e ve l s o f the h ighe r fr e que nc yno i s e por t ions o f the s pe c tr a we r e judge d to be we l l w i th ink n o w n t o l e r a b l e l i m i t s . T h e l o w f r e q u e n c y c o m p o n e n t s(be low 125 Hz ) ar e thus be l i e ve d to be mos t s ign i f i c ant .

I t c an be s e e n that many o f the fr e que nc y-no i s e l e ve l c om -binat ions ar e be low thos e o f the we l l e s tab l i s he d he ar ingthr e s ho lds o f Re fs . 31 and 32 . T hus the r e i s an ind ic a t ionthat there are signif icant extra-auditory effe cts such as noiseinduc e d hous e v ibr a t ions , or tha t the r e ar e loc a l iz e d ar e asin the ho us e s wh e r e the ins ide no i s e l e ve ls ar e c ons ide r ablyhighe r than the l imi te d me as ur e me n ts , and m ay ac tua l ly e x -c e e d the thr e s ho ld o f he ar ing .

C o n c l u d i n g R e m a r k sHo us e bui ld ings r e s pond r e adi ly to no i s e e xc i ta t ions and

their responses can play an im portant role in com mu nity reac-t ions to no i s e . Wal l s , f l oor s , c e i l ings and lar ge w indowsr e s pond main ly in the o i l c anning mo de s a t f r e que nc ie sbe low 100 Hz and the ir mot ions ar e c ontr o l l e d lar ge ly bythe beam elements. At higher frequencies th e sheathing panelsplay a greater role and are the dom inant e lem ents at frequen-c ie s above appr ox imate ly 300 Hz . M e as ur e d ac c e le r a t ionsfor a numbe r o f d i f fe r e nt type s o f no i s e inputs c or r e la tegeneral ly on th e bas is of p eak n oise leve l and increase l inearlyas the input le ve l inc r e as es . W al l and f loor m ounte d obje c t ssuch as lamps , pictures , mirrors , e tc . , may ratt le by excita-t ion of the main s tructure .

Cr i ter ia ar e inc lude d for pe r c e pt ion o f v ibr a t ion , the r a t -t l ing o f wa l l and f loor mounte d obje c t s , and no i s e induc e ddamage o f s e c ondar y s tr uc tur e s and fur ni s h ings .

References1 . A n o n y m o u s , R e c e n t H o u s e N o i s e A t t e n u a t io n D a t a a n d a n A v e r a g eH o u s e N o i s e A t t e n u a t i o n C u r v e , Soc. of Automotive Eng. AI R 1081(1969).2 . H . D . C a r d e n a n d W . H . M a y e s , M e a s u r e d V i b r a t i on R e s p o n s eC h a r a c t e r is t i cs o f F o u r R e s i d e n t i a l S t r u ct u r e s E x c i t e d b y M e c h a n i c a la n d A c o u s t i c a l L o a d i n g s , NASA TN D-5776 (1970).3 . W . H . M a y e s, D . S . F i n d l e y a n d H . D . C a r d e n , H o u s e V i b r a t i o n sS i g n i f i c a n t f o r I n d o o r S u b j e c t i v e R e sp o n se , N A SA SP-1 8 9 (1 96 9 ).4 . J .R . Y o u n g , A t t e n u a t i o n o f A i r c r a f t N o i s e b y W o o d - S i d e d a n d Brick-V e n e e re d F r a m e H o u se s , N A SA C R -1 6 3 7 (A u g u s t 19 7 0) .5 . W. Te mp e s t , Infrasound and L ow requency Vib ra t i on A c a d e m i c

P r e s s , L o n d o n , 1976), p . 9 .6 . D . E . B i s h op , R e d u c t i o n o f A i r c r a f t N o i s e M e a s u r e d i n S e v e r a lS c h o o l s , M o t e l s , a n d R e s i d e n t i a l H o m e s , J . Acoust. Soc. Am. 39,5 ,907-913 (1966).7 . B . L . C l a r k s o n a n d W . H . M a y e s , S o n i c B o o m I n d u c e d B u i l d i n gS t r u c t u r e R e s p o n s e s I n c l u d i n g D a m a g e , J . Acoust. Soc. Am. 51,2, 742-757 (1972).8 . H . D . C a r d e n , V i b r a t i o n C h a r a c t e r is t i cs o f W a i l s a n d a P l a t e G l a s s

W i n d o w R e p r e se n t a ti v e o f T h o s e o f a W o o d - F r a m e H o u s e , N A S ATP-1447 (May 1979).9. S . A . C l e v e n s o n , E x p e r i m e n t a l D e t e i m i n a t i o n o f t h e R a t t l e o f S i m -p l e M o d e l s , NASA TM 78756 (Ju ly 1978).1 0. D .G . S t e p h e n s, K .P . Sh e p h e rd , H . H . H u b b a rd a n d F . W. G r o s v e l d ,G u i d e t o t h e E v a l u a t i o n o f H u m a n R e s p o n s e t o N o i s e f r o m L a r g eWi n d Tu rb i n e s , _ N A S A TM 8 3 28 8 (M a rc h 1 9 8 2) .11 . D.G. S t e p h e n s a n d W . H . M a y e s , A i r c r a f t N o i s e - I n d u c e d B u i l d i n gV i b r a t i o n s : C o m m u n i t y N o i s e , A S M E S p e c i a l T e c h n i c a l P u b l i c a -t i o n 692 (1979), pp. 183-194.1 2 . D .S . F i n d l e y , V . H u c k e l a n d H . H . H u b b a rd , V i b r a t i o n R e s p o n s e so f T e s t S t r u c t u re N o . 2 D u r i n g t h e E d w a r d s A i r F o r c e B a se P h a s e o ft h e N a t i o n a l S o n i c B o o m P r o g r a m , N A SA LW P-2 5 9 (A u g u s t 1 9 6 6) .

1 3 . D .S . F i n d l ey , V . H u c k e l a n d H . R . H e n d e r s o n , V i b r a t i o n R e s p o n s e so f T e s t S t r u c t u re N o . 1 D u r i n g t h e E d w a r d s A i r F o r c e B a s e P h a s e o ft h e N a t i o n a l S o n i c B o o m P r o g r a m , N A S A L W P - 28 8 ( S e p t e m b e r1966).1 4. S t a f f - L a n g l e y R e s e a r ch C e n t er : C o n c o r d e N o i s e - I n d u c e d B u i l d i n gV i b r a t i o n s , J o h n F . K e n n e d y I n t e r n a t i o n a l A i r p o r t , R e p o r t N o . 3 ,NA SA TM-78727 (Apri l 1978).1 5. S t a f f -La n g l e y R e sea rc h C e n t e r : C o n c o rd e N o i se In d u c e d B u i l d in gV i b r a t i o n s , I n t e r n a t i o n a l A i r p o r t D u l l e s - - F i n al R e p o r t , N A S A T M74083 (September 1977).16 . N. D. Kel ley , Acoust ic N o i s e G e n e r a t i on b y t h e D O E / N A S A M O D - 1Wi n d Tu r b i n e , N A SA C P-2 1 8 5 (Fe b ru a ry 1 98 1 ).17. B l a s t i n g V i b r a t i o n s a n d t h e i r E f f e c t s i n Structures , Bureau o f M i n e sB u l l e t i n 6 5 6 ( W a s h i n g t o n D.C., 1971).

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18. Guide to the Evaluation of Human Exposure to Vibration and Shockin Buildings (1 Hz to 80 Hz), Proposed addendum to ISO standard2631-1974, International Organization for Standardization (September1977).19. Guide to the Response of Occupants of Buildings and Off-shore Struc-tures to Low Frequency Horizontal Motion (0.063 Hz to 2.0 Hz), Docu-ment No. ISO/TC 108/SC4 Draft Proposed DP 6897 (1981).20. Guidelines for Preparing Bio-environmental Impact Statements onNoise, Report of CHABA Working Group 69, National Academy ofSciences (Washington D.C., 1977).21. F.C. Nelson, Subject Rating of Building Floor Vibration, J. S o u n dVib. 8, 10 (October 1974).22. D. L. Allen and J.C. Swallow, Annoying Floor Vibrations-Diagnosisand Therapy, Sound and V ib . 9, 3 (March 1975).23. N. Broner, The Effects of Low Frequency Noise on People --AReview, J. Soland Fib. 58, 4, 483-500 (1980).24. D.E . Goldman and H. E. von Gierke, Effec ts of Shock and Vibra-tion on Man, Shoc k and V ibrat ion Hand book (McGraw-Hill BookCo., Inc., New York, 1961).25. S.M . Cant and P.A. Breysse, Airc raft Noise Induced Vibration in

l t I I

40

I

30

i o=>r 20

I S

Fifteen Residences Near Seattle Tacoma International Airport, Amer.Indus. Hygiene Assn. J . 34, 463-468 (October 1973).26. N.D. Kelley, A Methodology for Assessment of Wind Turbine NoiseGenerat ion , Presented at the 5th Biennial Wind Energy Conferenceand Workshop (Washington D.C., October 5-7, 1981).27. D.E . Goldman, Effec ts of Vibration on Man, H a n d b o o k o f N o i seControl C. M. Harris, Ed. (McGraw-Hill Book Co., Inc., New York,1975).28. R.T. Verillo, Investigation of Some Parameters of the CutaneousThreshold for Vibration, J . Acoust . Soc . Am. 34, 11 (1962).29. I. L. Vet and C. I. Holmer, In te ract ion o f Soun d Wav e s w i th Sol idStructures. Noise and Vibration Control L.L. Beranek, Ed. (McGraw-Hill Book Co., Inc., New York, 1971), pp. 270-357.30. E. E. Ungar, Structureborne Sound in Buildings: Needed PracticalResearch in Light of the Current State of the Art , NBS-GCR 80-248(June 1980).31. D.G. Stephens, D. P. Shepherd and F. W. Grosveld, Wind TurbineAcoustic Standards, NASA CP-2184 (1981).32. N.S. Yeowart and M. J. Ev0ns, Thresholds o f Audibility for VeryLow-Frequency Pure Tones, J . Acoust . Soc . Am. 55, 4, 814-818(1974).

IS IT POSSIBLE

YESRIONr

RION condenser microphones maintain Istability even underong term operatingenvironmental conditions of 40 C and 90% Ihumidity.

[ 0 I 91 Hours 181

0 0 0that h igh per formance, indust ry compat ib le condensermicrophones are now availab le for a reasonable pr ice?There is more RION's product testing of our microphonedesign, ut i l iz ing an exclusive vacuum sealingprocess, demonstrates that our condensermicrophones character ist ically perform withlow inherent noise, high sensit ivity, goodtransient response and immunity f romenvironmental ef fects of heat andhumidity. At RION, we knowour condenser~ i microphones and~ preamplifiers giveyou high perform-i ance, f lex ib i l i t y ,-~. '~ and dep end abi lityover a wide range.....~ t of measurement"~i ' application s. And.... no one else can doso much for so little.

S o u n d O u t R I O N ' s C o n d e n s e r M i c r o p h o n e s .o Call Us, Toll Free:

1 - 800 - 633 - 294 0R I O N n ~ n a t m t m , . m c817 Wheeler Ave., Hu ntsv ille, AL 35801 *In AL, (205 ) 533 - 9290I

I n th e N e x t I s s u e . . . Dosimeters Impulsive Noi se and the OS HA Hearing Conservation Amen dmen t The Decaying F low Technique: A Metho d for the Rapid Acquisition o f Data Relating to

Regenerated Noise in Ventilation Systems Direct Measurement o f Transmission Loss o f Aircraft Structures Using the Acous tic Intensity

ApproachN o v e m b e r - D e c e m b e r 1 9 8 2

N O I S E C O N T R O L E N G I N E E R I N G J O U R N A LThese articles may be subject to change

V o l u m e 1 9 / N u m b e r 2 5 5

hubbard 1982 noise induced house vibrations airports

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