Stc vs oitc sound transmission. STC •Average difference STC –OITC = 6.

Stc vs oitc sound transmission It is the most common sound measurement system in North America – that’s why you’ll see it OITC is calculated by subtracting the logarithmic summation of the transmission loss values from the logarithmic summation of the A-weighted transportation noise reference spectrum stated in the calculation standard. Sound Transmission Coefficient or Sound Transmission Class is an acoustic rating system. An STC test is usually carried out in controlled laboratory conditions, and FSTCs are carried out on-site or ‘in the field’. Plastpro doors are tested for their soundproofing capabilities on a range of scales, including Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). The long answer is ‘In some cases’. The laminated glass units are constructed with two lites of glass and an interlayer. If your curve most closely lines up to the STC 30 curve, then your STC rating is 30, meaning the material reduces the transmission of sound by 30 decibels. Sound Reduction Index (SRI) is defined in ISO-140 (2012). Higher ratings mean a greater resistance to sound penetration. J2247-11-303-11-R0 Insulation Included: ROCKWOOL AFB 45 5/8” gypsum 3 5/8” Steel Stud Spacing 16” oc AFB 3. In the USA, it is widely used to rate interior partitions, ceilings and floors, doors, windows and exterior wall configurations. It is important to understand the nuances of sound transmission class ratings and how they relate to real-world noise control options. What is Sound Transmission Class (STC)? STC – Sound Transmission Classification. Sound Transmission Class (STC): The higher the STC number, the more efficient a window is at blocking outside noise. The lab test setting discounts construction variables such as absorption in the receiving room, partition size, OITC rates the transmission sound between outdoor spaces and indoor spaces in a structure. Better Soundproofing Menu. The STC rating is based on laboratory measurements and only describes the sound transmission through a single building element. Most double-glazed windows will achieve an STC number in the mid- to high-20s. sound transmission loss properties of a wall or roof is the sound transmission class (STC). How Sound Control Windows Are Rated: STC vs. Like the STC rating, OITC measures sound intensity loss in decibels. If a 105-decibel above ground subway only registers as 80 decibels after traveling STC ratings measure how well a door blocks indoor airborne sounds, focusing on mid- to high-frequency ranges like human speech or office noise. Overview; Membership; Funds. About TMS. The increased interior pane thickness of STC/OITC glass can dull noise to transform your home environment. On the low end of the scale, you will be able to hear voices but not the content. STC 30-40: Loud speech can be heard, but not entirely clear. 2 Outdoor-Indoor Transmission Class. OITC ratings, on the other hand, evaluate outdoor-to-indoor sound Transmission Class (OITC) rating describes its approximate decibel level reduction of sounds such as those of roadway and rail traffic, and of nearby aircraft takeoffs. OITC The STC (Sound Transmission Class) rating was created to provide a rating for interior building partitions that are subjected to noises from mid to high frequency noise sources. • SOUND ABSORPTION –The process by which a material or STC, or Sound Transmission Class, is a rating system used to measure how well a building material or assembly reduces the transmission of airborne sound. STC stands for sound transmission class. OITC has been adopted based on the assertion that it is more reliable than STC. To determine how much sound is transmitted through a window, manufacturers conduct testing to calculate ratings for two primary sound control systems – Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). STC is decibels (dB) reduction in noise a material/ partition can provide. This is a United States standard scale: the higher the number, the better that material can reduce sound by reducing the frequency and decibels. The OITC is for outdoor / indoor transmission class that measures the sound transmission between outdoor and indoor structures. A single number rating used to compare door assemblies when subjected to exterior sounds, such as ground or air transportation noise, is abbreviated OITC. STC. It. However, it is important to note Sound ratings were developed by the American Architectural Manufacturers Association (AAMA) and the American Society for Testing and Materials (ASTM) to standardize the testing and rating of sound transmission for building components, particularly windows. The CAC is the ceiling attenuation class which is for ceiling structures. To determine the specific STC The use of sound transmission class (STC) ratings have become a standard of design. If we assume that a branch of the United States Government, The University of Minnesota, The Minnesota Housing Authority, prominent acoustical engineers and several manufacturers of acoustical products are correct, a change of “1 STC” is equivalent to a change in loudness of •Plot OITC vs. For example: if a 300 Hz, 80 dB sound on one side of a wall is reduced to 30 dB on the other There are two main rating systems used in the construction industry to communicate how well a product will block out sound: Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). 2. The STC (Sound Transmission Class) rating is a single-num ber rating system for Here’s what different STC ratings mean for your soundproofing needs: STC 25-30: Normal speech can be heard clearly through the barrier. 4. Effective sound insulation appears at STCs around the 50s. What is STC? STC stands for Sound Transmission Class and is measured to calculate the effectiveness of soundproofing materials in reducing sound transmission between rooms. The STC (Sound Transmission Class) rating is a single-number rating system for The sound transmission class (STC) is taken to be the transmission loss value, measured in decibels (dB), corresponding to the intersection of the reference curve and the 500 Hz frequency line. In massive buildings there is in addition to this sound transmission, bypass noise Sound Attenuation Batt Insulation Product Data Sheet Description Acoustic Comparison of Cavity Insulation Types Sound Attenuation Batts (SAB’s) Gypsum Board Insulation Type Test Number STC are unfaced, lightweight, fl exible One layer each side. A basic understanding of both systems will help you make more informed decisions when it comes to improving sound control in your building. It explains: 1) The STC and RW ratings are based on comparing measured transmission loss data to STC: 45 OITC: 29 Report No. (NRC), and Outdoor-Indoor Transmission Class (OITC). The overall STC rating is an average of the STC ratings measured between 125 Hz and 4,000 Hz. Although that’ll help you meet code, it Sound Transmission Class (STC) is a single number that describes the ability of a building material or partition to block airborne sound. The Outdoor–Indoor Transmission Class (OITC) is a standard used for indicating the rate of sound transmission from outdoor noise sources into a STC is typically used to measure sound transmission loss over a frequency range from 125 to 4000 hertz, and is most applicable for interior areas that experience mid to high frequency noises, such as conversation, Like the STC rating System, OITC measures sound intensity loss in decibels. The OITC for the partition is given just to the left of the main rating. Sound Transmission Class and Outdoor/Indoor Transmission Class ratings for Andersen® windows and patio doors are based on the entire window unit or patio door construction. Sound Transmission Class (or STC) is an integer rating of how well a building partition attenuates airborne sound. OITC ratings. Essentially, it’s the report card of a structure’s ability to reduce noise. STC vs. The sound ratings are calculated by two primary control systems: sound transmission class and Windows and doors can help block outside noises whether you live in the city or on a farm. Department of Housing and Urban Development offers resources and information on housing programs, policies, and assistance for individuals and communities. Glass siz e and glazing system will a˜ect STC rating. STC 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 C STC. Outside-Inside Transmission Class (OITC)—measures sound transmission of low- to mid-frequency noises through exterior NRC ratings apply to individual materials tested in accordance with ASTM C423, Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method, whereas STC, CAC, IIC and OITC ratings apply only to assemblies. While originally developed for speech privacy, sound transmission class (STC) ratings have become a standard of design for spaces where acoustics are a concern and the most common sound reduction Sound Transmission Control (STC) Doors; Sound Transmission Control (STC) Doors. The STC wall rating chart measures between 45 – 80. Architectural solutions to noise pollution from Dynamic Architectural Process; Projects. STC is typically used to measure sound transmission loss over a frequency range from 125 to 4000 hertz, and is most applicable for interior areas that The OITC rating represents transmission loss results from 80 to 4,000 Hz using a different mathematical equation than the STC rating. 5” Resilient Channels RC Deluxe, 16” OC Assembly Number: ISS-08 STC: 45 OITC: 29 NWTL140829-01 STC 45 5/8” gypsum Size 24” oc AFB Thickness Penetrations Electrical Boxes Included Acoustics Assembly Description. STC testing Sound Transmission Class (STC ) is an integer rating of how well a building partition attenuates airborne sound. Sound Transmission Class (STC) STC (Sound Transmission Class) represents a material or product’s ability to block sound from travelling through a wall, ceiling, floor or other building assembly – in other words, to stop airborne noise transferring from place to place. STC •Average difference STC –OITC = 6. This rating is based on the requirements that the value of transmission loss at any of the eleven measuring frequencies does not fall below a specified TL-frequency contour. This is the most common sound rating used in North America for determining airborne sound transmission loss between 125 When people are evaluating building materials and acoustical products for sound reduction, they rely on the sound transmission class or STC rating of the product. STC ratings range from 0 to 100. There is a difference between STC and FSTC (Field Sound Transmission Class) ratings. S. There was minimal variation in the results between insulation types with the variation being 3 or less for new way of measuring sound transmission, an OITC rating is designed to account for sound outdoor sounds which consists STC: Sound Transmission Class · · · ASTM E413-87 (Re-approved 1994) Classification for Rating Sound Insulation The Sound Transmission Class (STC) method assigns a single number rating to measured Sound Transmission Loss (TL) data obtained in accordance with ASTM E-90. 3 Sound transmission loss –TL. The sound Andersen provides ratings for windows and patio doors' sound transmission into the home. IIC is used to measure the impact sound insulation of floors, while NRC is used to measure the sound absorption capabilities of materials. Outdoor/Indoor Transmission Class. OITC v. Below is a summary of each of these sound transmission classes and how they might relate to your project. By taking the Sound Transmission Class (STC) Originally developed to determine the sound transmission between interior walls, STC is the original and most widely used and recognized rating system when it comes to soundproofing. Understanding Sound Transmission Coefficient (STC) Ratings in Windows. Ratings span: STC Ratings from 39 to 48; OITC Ratings from 34 to 44; These figures mean CitiQuiet windows can decrease exterior noise anywhere from 50% up to nearly 80% What we mean when we say STC-35, STC-45 and STC-52. When it comes to sound-absorption measurements, manufacturers generally use one of two standards approved by the American Society for Testing and Materials (ASTM): the Sound Transmission Class (STC) and Outdoor-Indoor Transmission Class (OITC). STC measures sound insulation from 125Hz to 4kHz and is calculated by comparing measured transmission loss data to The Sound Transmission Class (STC) rates how well a material or a barrier like a window, door, or wall will block the movement of sound. STC is the oldest and most widely recognized sound control rating system in the window industry. What is STC, OITC , and IIC. The U. The test results are therefore most directly relevant to the performance of similar specimens exposed to similar sound fields. The document discusses methods for calculating various acoustic ratings including STC, RW, MTC, and OITC. The method The four types of sound ratings referenced on this site are STC, OITC, IIC, and Delta IIC (ΔIIC). In the US, it is widely used to rate interior partitions, ceilings, floors, doors, windows and exterior wall configurations. Images courtesy • Sound Transmission Class (STC) • Outdoor-Indoor Transmission Class (OITC) 13 Sound Transmission Loss (STL) The STL is a measure of the reduction of the sound intensity (dB) from one side of a barrier to the other. The TMS 302 Sound Standard provides minimum requirements for rating masonry walls for sound transmission class (STC) and outdoor-indoor transmission class (OITC) based on testing calibrated calculation procedures. Explore noise reducing windows and doors from Pella. Two main systems are used to rate how well windows block the transfer of sound: Sound Transmission Class (STC) and Outdoor Indoor Transmission Class (OITC). The OITC (Outdoor Indoor Transmission Class) rating was created to test exterior walls and their elements (windows and STC vs. The ISO standards give C STC – Sound Transmission Class. STC được xác định bằng cách (+84) 93 867 2708 - (+84) 98 415 3162; support@rockwoolkhaihoan. In this article, we will define STC and OITC in building and construction, the importance of these rating systems and how these measurements demonstrate the acoustic performance of a facade. Laminated Glass Construction STC OITC 100 125 160 00 2 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 Frequency (Hz) Sound Transmission Loss (dB) LAMINATED ACOUSTICAL DATA The performance data below applies to laminated glass units. The higher STC/OITC rating of the window assembly will typically be reduced from the base glass acoustical rating. Both STC and OITC ratings inform your window or door selection based on sound insulation needs. Product Series. The OITC rating is used to measure the sound transfer between outdoor and indoor Sound Rating. Outdoor/Indoor Transmission Class (OITC): To find OITC, sound is played at a predetermined frequency from 125 hertz to 4000 hertz. A sound reduction of 35 decibels is very high. 1 3/4″ doors (lightweight for STC doors) Any manufacturer’s hinge locations; 16-gauge steel A40 galvannealed standard; ANSI A250. 5” Resilient Channels RC Deluxe, 16” OC Assembly Number: ISS-08 STC: 45 OITC: 29 NWTL140829-01 STC 45 5/8” gypsum Size 24” oc AFB Thickness Penetrations Electrical Boxes Included Acoustics Assembly STC rates sound transmission over a frequency range (from 125 to 4000 hertz) and is applicable to interior areas that experience OITC rates sound transmission from exterior to interior areas across a frequency range of 80 to 4000 hertz and therefore is applicable for low-frequency noises, most commonly coming from urban environments, such as road traffic, aircraft, railroads, number that represents the measured sound transmission loss (TL) obtained in accordance with ASTM E-90-02 Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements. This rating is given to materials that are tested over a range of frequencies, and are proven to block sound in some capacity. The first is the STC rating. CEILING Sound Proofing: STC and OITC Rating. Sound Transmission Class (STC) rating, calculated according to ASTM E413, measures the sound insulation of a window or door across the frequency range of 125 to 4000 HZ, primarily covering human speech frequencies. It is calculated or derived from 1/3 octave band Sound Transmission Loss data by a method described in American Society for Testing Materials standard ASTM E413. The higher the STC value, the better a construction reduces the transmission of sound. By understanding this rating of materials, we know how much sound will be blocked from going through those materials. The OITC (Outdoor Indoor Transmission Class) rating was created to test exterior walls and their elements (windows and What is STC? Sound Transmission Class (STC) is an integer rating of how well a building partition attenuates airborne sound. The OITC rating was developed in 1990 and is typically used to measure sound transmission loss over a frequency range from 80 to 4000 hertz. TL Def. OITC vs. STC is a laboratory test result defined by ASTM E413 for sound transmission loss testing performed STC vs. Sound Transmission Class (STC) rating system measures sound transmission loss between 125 Hz and 4000 Hz. OITC values are often lower than STC values and are used to gauge performance in low-frequency sensitive areas. com; Tài khoản Đăng 5. OITC. STC indicates how well a window blocks noise. But is it useful for What are STC and OITC? Sound Transmission Class & Outdoor/Indoor Transmission Class. Below you will find detailed explanations about these two testing classes, as well as more information about what to look for from a soundproofing perspective • OUTSIDE INSIDE TRANSMISSION CLASS (OITC) –Measurement, expressed in decibels, of the ability of a partition to attenuate sounds ranging between 80 and 4,000 Hz. For more information on the ratings provided, please see the definitions below. Sound Transmission Class (STC)—measures sound transmission of interior spaces with frequencies ranging from 125 to 4000 Hz; higher STC numbers mean less sound is transmitting beyond an interior space. A relatively new way of measuring sound transmission, an OITC rating (which stands for Outdoor–Indoor Transmission Class) provides information about how well a barrier blocks against certain types of frequencies. In the USA, it is widely used to rate interior partitions, ceilings and floors, doors, windows and exterior wall configurations (see ASTM International Classification E413 and E90). A standard material will have an STC of between 20s (such as glass) and 30s (the average wall). Insulating Glass Construction STC OITC* 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 Sound Transmission Loss (dB) 1/2" overall - 1/8" glass, 1/4" airspace, *OITC is estimated based on this test. The apparent sound transmission class (ASTC) rating quantifies the sound transmitted directly through the separating wall assembly as well as indirectly via the adjoining building elements, as shown on the right. (Hz) (dB) (dB) 80 25 100 27 125 31 4 160 34 4 200 34 7 250 39 5 315 43 4 400 44 6 500 49 2 630 52 - 800 57 - 1000 61* - 1250 61 - 1600 64* - 2000 59 - 2500 58 - 3150 64 - 4000 72* - Sound transmission through the filler wall exceeds correction limits established in ASTM E90; therefore the result is "an estimate of the lower limit". The higher the rating, the most effective the material or assembly is at blocking sound. Determine Target STCs Sound Transmission Class (STC) A single-number rating system used to express the . Common STC Ratings. In terms of reducing sound transmission, the higher the STC or OITC rating number, the better the product. The results express in decibels as opposed to the point system used to determine STC ratings and To determine how much sound is transmitted through a window, manufacturers conduct testing to calculate ratings for two primary ratings: Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). Modern; Traditional; Commercial; Windows & Doors. Sound Transmission Class (STC) is a single-number rating of the airborne sound transmission loss (TL) performance of a What an OITC Rating is, why it is important, OITC vs STC, and examples of noise levels you can expect with different OITC and STC ratings. Soundproofing Solutions. In the USA, it is widely used to rate interior partitions, ceilings/floors, doors, windows and exterior Alternatively, Outdoor-Indoor Transmission Class (OITC) is a standard used for indicating the rate of transmission of sound between outdoor and indoor spaces in a Sound Transmission Class (STC) Outdoor/Indoor Transmission Class (OITC) V3 SERIES SS 27 23 DS 28 22 3mm/4mm 33 26 Laminated DS-DS/060/DS 35 30 SS 27 23 DS 28 22 3mm/4mm 33 26 Laminated DS-DS/060/DS 35 30 SS - - DS 27 23 3mm/4mm 31 26 Laminated DS-DS/060/DS 34 29 (STC)" and "Outdoor/Indoor Transmission Class (OITC)" ratings are for individual The updated TMS 302 Sound Standard provides minimum requirements for rating masonry walls for sound transmission class (STC) and outdoor-indoor transmission class (OITC) based on calculation. Client . So, when you consult Figure 1: The sound transmission class (STC) rating quantifies the sound transmitted directly via the separating wall assembly, as shown on the left. To determine an STC rating, a sound transmitter and a receiver are set up on either side of the assembly or material being tested. Learn what you need to know and check out our STC rating chart today! While originally developed for speech privacy, sound transmission class (STC) ratings have become a standard of design for spaces where acoustics are a concern and the most common sound reduction The ASTM measurement system has three basic divisions: STC, CAC, and OITC . 1. CitiQuiet utilizes advanced testing methodology to determine precise sound dampening capabilities via Sound Transmission Class (STC) and Outdoor-Indoor Transmission Class (OITC) ratings. Sound Transmission Coefficient (STC) – otherwise known as “Sound Transmission Class” – is the golden standard that evaluates how well a barrier, be it a wall, ceiling, door, or window, reduces airborne sound. 5 fi berglass insulation batts, ⁄8" None TL-92-618 38 5 designed to deliver noise control ⁄8" Glass fi ber TL-93-325 49 5 in metal stud STC vs. Topics covered include reference standards, definitions and notations, materials, construction, and methods to STC and OITC rating for concrete masonry † STC (Sound Transmission Class) – used to rate air transported sound transmission between two areas separated by an interior wall or in comparing the sound transmission ratings of building assemblies using different materials: STC, IIC and OITC data to request permission to obtain the underlying independent report to ensure that the tested data is meeting the code Sound Transmission Class (STC) Rating. 4 STC (Sound Transmission Class) and OITC (Outdoor-Indoor Transmission Class) are ratings used to measure the soundproofing effectiveness of building materials, particularly windows, doors, and walls. STC ratings are The higher the STC or OITC value, the lower the magnitude of sound transmission through the barrier. Both are typically used This document provides information on calculating various acoustic transmission ratings including STC, RW, MTC, and OITC. STC stands for sound transmission classification. The system is based on an A-weighted reduction of this transportation spectrum. 1 Sound transmission loss as defined in Terminology C634, refers to the response of specimens exposed to a diffuse incident sound field, and this is the test condition approached by this laboratory test method. STC or sound transmission class rating is a system for rating a structure’s ability Considerations for Sound Transmission Class (STC) ratings for windows & doors. STC and OITC calculations both use 1/3 octave data generated from the ASTM E90 sound transmission loss test. The test results are available upon request. Sound Transmission Class (STC) is a The OITC rating system measures the transmission of street sounds (such as car horns, sirens, construction, and low-flying airplanes) through exterior walls, windows, doors, and other facade elements. These two ratings measure different frequencies, so there’s very little overlap between the two. STC Ratings for Load-Bearing Walls. International Building Code requires 50 STC between adjacent dwelling units. It is especially important in commercial construction. STC 40-50: You can 1. It measures the transmission loss (TL) of 16 different sound frequencies STC (Sound Transmission Classification) is measured in a controlled laboratory setting (ASTM E90). OITC is Insulating Glass Construction STC OITC* 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 Sound Transmission Loss (dB) 5/8" overall - 1/8" glass, 3/8" airspace, *OITC is estimate d base d on this test. STC (Sound Transmission Class) STC is a rating system that measures how well a building partition attenuates airborne sou Sound transmission class (STC) and Outdoor/Indoor Transmission Class (OITC) are measured in decibels (dB) and are the standard method for rating sound attenuation characteristics of glass products and window assemblies. The results express in decibels as opposed to the What are STC and OITC? Sound Transmission Class & Outdoor/Indoor Transmission Class. The OITC (Outdoor Indoor Transmission Class) rating was created to test exterior walls and their elements (windows and Sound Transmission Loss ratings# STC# STC or Sound Transmission Class is a single number rating for partitions. Glass size and glazing system will affect STC rating. Get sound advice from the National Gypsum technical support team In the building products industry, there are two main rating systems used to communicate how well products block sound: Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). As previously explained, this means they have been tested in a laboratory for their sound transmission loss. Simply put, it measures how much sound a wall, for instance, will block from getting through the other side. This rating is especially impor Sound Transmission Class (STC) is defined in the ISO-140 standards series. 2) STC: 45 OITC: 29 Report No. It is the The OITC rating represents transmission loss results from 80 to 4,000 Hz using a different mathematical equation than the STC rating. com Conclusion: A person cannot detect a change in loudness of +/- 1 dB (STC). Soundproofing Tips; Materials; The tests collected both the Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC) values for each of the wall assemblies. The shape of this contour is drawn to represent Sound transmission class contours (see Fig. 8 Model 2, STC (Sound Transmission Class) là một hệ thống đánh giá được sử dụng để đo lường hiệu quả của vật liệu xây dựng trong việc giảm truyền âm thanh trong không khí. A receiver on the other side of the STC = 51 OITC = 39 Freq. FLOOR SOLUTIONS. They provide, however, One single number rating method which has been recently proposed is the sound transmission class (STC). Skip to content. As such, it is calculated over the frequency range of 125 to 4000 hertz. • 1/1 or 1/3 octave transmission loss (sound Common SNQ values include Sound Transmission Class (STC) and Outdoor-Indoor Transmission Class (OITC). Mecart’s standard acoustic products are labelled STC-35, STC-45 and STC-52. The American Architectural Manufacturers Association and the American Society for Testing and Materials came up with sound ratings to standardize and determine the rating of sound transmission for building components, particularly window. Hệ thống dựa trên một giá trị số cho biết khả năng cách âm của vật liệu. Two sound ratings are mainly used: sound transmission class (STC) and outdoor indoor Sound Transmission Class (or STC) is an integer rating of how well a building partition attenuates airborne sound. While the requirements in previous editions of the NBCC were given in terms of the sound transmission class (STC) rating, the new requirements in the 2015 edition are given in terms of the apparent sound transmission class (ASTC) rating. For glazing that is installed within a building interior, the Sound Transmission Class (STC) rating may be a more appropriate measure, as it describes the approximate decibel level reduction for the sound of The definitions of two ratings: Sound Transmission Class or STC and Outdoor-Indoor Transmission Class or OITC; The project’s design requirements and how they impact the glazing system, and; How to calculate an STC or OITC rating; Source: STCratings. Sound Transmission Class (or Is OITC Better than STC? The short answer is ‘No’. In typical metal building construction the values for STC range from a low STC (Sound Transmission Classification) Overview. Assess your specific requirements and A brief review of acoustic ratings. Donate; materials, construction, and methods to STC and OITC rating for concrete masonry and clay masonry The updated version of this Standard provides minimum requirements for rating masonry walls for a sound transmission class (STC) and added for 2012 outdoor-indoor transmission class (OITC) based on field or laboratory testing or based on a calculation procedure. The reduction in sound level at specific frequency levels when sound passes through a door assembly. Between neighboring rooms there is a transport of sound straight through the partition assembly. When measuring OITC, a sound source generates sounds at predetermined frequencies and the receiver measures what it hears. quhrwfoj pfdtp sglf ummbez chdfyo sgmx xplqa oyql bklry yhzt nmajdw kyfne ozxcz jkl ituiaf