TECTUM Inc. P.O. Box 3002 Newark, OH

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M November 2010 G TECTUM Ic. P.O. Box 3002 Newark, OH 43058 www.tectum.com.

1 M November 2010 G TECTUM Ic. P.O. Box 3002 Newark, OH t: The use of acoustical absorbets, acoustical isolatio or ay chages or additios to the structure to correct acoustical faults or improve the acoustical eviromet. : The sciece of soud, icludig its productio, trasmissio ad effects. e Soud trasmitted through air as a medium rather tha through solids or the structure of a buildig. mb t ac : Total of all oise i a system or situatio, idepedet of the presece of the desired sigal. Ambiet oise may come from the buildig's mechaical equipmet, outside traffic, activities i adjacet room or other sources ot directly related to the desired sigal. A sigle umber ratig system used for comparig buildig system: ad sub-systems for speech privacy purposes. The ratig is desiged to correlate with trasmitted speech itelligece betwee office spaces. al: ASTM Iteratioal is oe of the largest volutary stadards developmet orgaizatios i the world-a trusted source for techical stadards for materials, products, systems, ad services. Kow for their high techical quality ad market relevacy, ASTM Iteratioal stadards have a importat role i the iformatio ifrastructure that guides desig, maufacturig ad trade i the global ecoomy. : Reducig the itesity of a soud sigal, the lowerig of soud level. The efficiecy of a material to resist the trasmissio of airbore soud measured i decibels. ac ev : The ormal soud level preset i the space above which speech, music or similar specific wated soud must be preseted. ac : NC- levels usually refer to steady, cotiual backgroud levels withi a space or eighborhood, as opposed to specific oises or itermittet activities occurrig there. The level of a performig orchestra or had, for example, ormally is ot expressed i this way, hut i a dba or Soud Pressure Levels i various frequecy hads. All umbers listed may vary as much as +5 poits i specific areas. ev : A sloped or cated surface cotiguous with a. vertical or horizotal surface. ow: The maximum compoet of deviatio i the vertical plae or a mai ruer, cross ruer or wall moldig where the cetroidal axis of these structural compoets has bee permaetly deformed from ed to ed ito the shape of a simple regular curve durig the maufacturig process. TM Trademark of Tectum Ic. Page 1 of 6

2 amb : The amout of upward bow rolled ito a suspesio member to offset deflectio uder the load of lights, acoustical paels, air diffuser, etc. A measure of reductio i soud trasmissio via pleum path betwee two rooms determied i accordace with ASTM EI414 ad plotted decibel reductio (trasmissio loss) obtaied at 16 frequecies agaist a stad reflectace curve, i accordace with ASTM E413. uspe : Etire etwork or grid of structural compoets that provides support for acoustical ceilig tile, acoustical ceilig paels, lightig fixtures ad air diffusers. Ceiligs ad Iterior Costructio Associatio : A recessed pael or dome i the ceilig. : The etire sequece of movemet of a particle (durig periodic motio) from rest to oe extreme of displacemet, back through rest positio to the opposite extreme of displacemet ad back to rest positio. b : Uit for measurig soud itesity. A divisio of a uiform scale based upo te (10) times the commo logarithm of the ratio of two like quatities proportioed to power or eergy. Zero o the decibel scale correspods to a stadardized referece soud power of watts. The chart below demostrates how soud pressure levels compare with itesity expressed i uits: : The sag or bowig dow of a member simply supported caused by superimposed loads (i.e., lights, acoustical tile). Deflectio is limited to L/360 of the spa, per ASTM C-635. codes. ds: Egieerig criteria used to establish or meet safety factors as set forth by buildig Roughly, the ability of a soud wave to "flow" aroud a obstructio or through opeigs with little loss of eergy. : A circular, square, rectagular or slot outlet located i the ceilig of a room through which supply air is ormally discharged o a plae approximately parallel to the ceilig. Page 2 of 6

3 space. p Dispersio of soud withi a space so that there is uiform eergy desity throughout the The scatterig or distributio of soud i a space. : Ay chage i the trasmitted soud which alters the character of the eergy-frequecy distributio withi the sigal so that the soud beig received is ot a faithful replica of the source soud. b The patter of soud itesity levels withi a space; also, the patters of soud dispersio as the soud travels withi the space. cho: Ay reflected soud which is loud eough ad received late eough to be heard as distict from the source. ri A suspesio system which, after istallatio of all elemets of the ceilig, leaves the mai ad cross ruers exposed whe viewed from below. Those ratigs of a tested assembly which are exposed i hours ad applied to floors, roofs, beams, colums ad walls. : A multiple echo set-up betwee parallel, reflectig surfaces. req : The umber of times per secod that the soud pressure alterates above ad below the ambiet atmospheric pressure. Each complete alteratio is called a cycle ad frequecy is expressed i Hertz (Hz) or cycles per secod (CPS). ri b : Mai ad cross ruers which iterlock to support the acoustical, lightig, air diffusers, etc., of the ceilig system, with the secodary fuctio of havig aesthetic acceptace whe viewed from below. These members may be made from steel or alumium i various cofiguratios. eg ays: Heatig degree days are a idex of "cold" useful i eergy cosumptio calculatios. The umber of heatig degree days is calculated for each day by subtractig the day's mea temperature from a base temperature (usually, 65F). The daily totals are accumulated for each moth ad the mothly totals are accumulated for the "heatig year" from July through Jue. The amout of eergy cosumed for heatig is closely correlated to these heatig degree days. zo ceilig. e: The plae through the cetroidal axis of the member parallel to the plae of the The uit desigatio for frequecy of a soud wave, formerly cycles per secod (CPS) - oe cycle per secod. : The rate of soud eergy trasmitted i a specific directio through a uit area. A stadard used to determie the maximum vertical deflectio allowed the horizotal member (supported) for acceptace. "L" is the distace betwee hager (support) poits i iches. The "360" is a pure umber without quatity. Therefore, the distaces i iches divided by 360 gives a result i iches of maximum allowable vertical deflectio. Page 3 of 6

4 i t The umber desigatio idicatig the percetage of light reflected from a ceilig's surface, i accordace with ASTM E1477. i : They are i itegral part of the ceilig system icorporatig the air diffuser elemet with the orifice face at the ceilig lie, mechaically locked ito the grid system. : The effect o the hearig apparatus of varyig soud pressures ad itesities. ev : The soud pressure level i decibels (relative to microbar) of a simple toe of 1,000 c.p.s. frequecy. aski The icrease i threshold of audibility of a soud ecessary to permit its beig heard i the presece of aother soud. : The quality of matter which permits it to resist acceleratio; the quality of matter which produces the effect of iertia. ax wab The weight placed o the suspesio system which if exceeded will cause a greater deflectio, i the mai or cross ruer, tha is allowable for safety ad to meet ASTM specificatios. This is frequetly defied as L/360. t : Stated i iches, a egieerig computatio of effectiveess of a grid member to resist deflectio of that member. t: Ay moutig, attachmet system or apparatus which permits room surfaces or machiery to vibrate ormally without trasmittig all of the eergy of vibratio to the structure. : Uwated soud. v v ): Series of criterio curves that portray soud pressure levels for backgroud oises which geerally should ot be exceeded, or should be maitaied, i various huma eviromets. ed : The reductio level of uwated souds by ay of several meas. ed t): A measure of soud absorbed by a material. The sigle umber desigatio represetig the average of the soud absorptio coefficiets of a material at 250 Hz, 1000 Hz ad 2000 Hz rouded to the earest 0.05 whe tested i accordace with ASTM C-423. ve a s: A octave is the iterval betwee two souds havig basic frequecy ratio of two. The physical respose to frequecy. The subjective respose of the hearig mechaism to chagig frequecy. a : The atural, sympathetic vibratio of a material at a particular frequecy resultig for excitatio by a vibratio of that frequecy. ev b : The prologatio of soud withi a space after the source has stopped. abi Oe square foot of a surface havig perfect absorptio, a absorptio coefficiet of Page 4 of 6

5 abi : Relates room volume ad total acoustical absorptio to reverberatio time: T =.05V/A T = Reverberatio Time i Secods V = Room Volume i Cubic Feet A = Total Absorptio i Sabi : A fasteer which combies the fuctios of drillig ad tappig. a i : A fasteer which taps its ow threads i a pre-drilled hole. hearig. A vibratio i a medium; usually i the frequecy rage capable of producig the sesatio of by a surface. p t: Fractio of icidet soud eergy absorbed or otherwise ot reflected ks: Ay opeig which permits airbore soud trasmissio. : The average deviatio i atmospheric pressure above or below the static value due to a soud wave (aalogous to alteratig voltage). ra A sigle umber value describig the ability of a system of materials to isolate oe eclosed space from aother acoustically. A ratig method (per ASTM desigatio E413) based o the requiremet that the value of trasmissio loss at ay of the 16 measurig frequecies does ot fall below the specified limits of the TL frequecy cotour. ave: A disturbace which is propagated i a medium i such a maer that at ay poit i the medium the displacemet is a fuctio of the time. a The distace betwee two supportig members. : Descriptio of the resolutio of a soud wave ito compoets, each of differet frequecy ad (usually) differet amplitude ad phase. specific agle. : The atteuatio of soud i db, as it is reflected from a ceilig, wall, etc. at a 344 meters per secod or 1,128 feet per secod at 25 degrees C or 77 degrees F. The speed of soud is a importat cosideratio i large room acoustics where the relative timig of soud frots (direct ad reflected) has a strog bearig o soud quality. e Soud eergy trasmitted through the solid media of the buildig structure. ra The propagatio of a vibratio through various media. ra : A measure of the decrease is soud level as it passes through a structure. Variable with the frequecy of the soud. a the ceilig. Noise: iterferig soud, whatever its source or ature. e: The plae through the cetroidal axis of the member perpedicular to the plae of Page 5 of 6

6 a The audible sigals which commuicate ecessary ad desirable iformatio or stimuli to the listeer. ave e t The distace a soud wave travels durig each complete vibratio or cycle. Page 6 of 6

Measurement uncertainty of the sound absorption

Measurement uncertainty of the sound absorption Measuremet ucertaity of the soud absorptio coefficiet Aa Izewska Buildig Research Istitute, Filtrowa Str., 00-6 Warsaw, Polad a.izewska@itb.pl 6887 The stadard ISO/IEC 705:005 o the competece of testig