Acoustical Testing Services and More

Laboratory Testing


Laboratory Testing
Services by Standard

Accredited ASTM E90 - Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements. ISO/IEC 17025:2017 accredited through A2LA Certificate 4240.01

ASTM C423 - Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method

ANSI/ASA S12.51/ISO 3741 - Determination of Sound Power Levels and Sound Energy Levels of Noise Sources Using Sound Pressure – Precision methods for reverberation test rooms

ISO/IEC 17025 Accreditation assures that your test results will be recognized and trusted by your clients and customers around the globe. A2LA is a signatory to the International Laboratory Accreditation Cooperation (ILAC) Mutual Recognition Arrangement (MRA) and the International Accreditation Forum (IAF) Multilateral Recognition Arrangement (MLA).

Laboratory Testing 

Services by Type

Sound Transmission Loss - Measures sound transmitted through walls, floors, windows, doors and other building elements. Results provide ⅓ octave band Transmission Loss (TL) and Sound Transmission Class (STC) numbers. Data is used by acousticians, architects and engineers to design and specify appropriate noise isolation between architectural spaces. ISO/IEC 17025 accredited through A2LA Certificate 4240.01

Sound Absorption - measures sound absorbed by a panel or screen. Provides ⅓ octave band absorption coefficients, Noise Reduction Coefficient (NRC), Sound Reduction Rating (SRR). Data is used by acousticians, architects and engineers to specify appropriate room finishes for acoustic control

Sound Power – Measures and quantifies the entire amount of sound energy produced by a device. Sound power, unlike sound pressure data, allows apples-to-apples comparisons of sound data between machines or devices that is not affected by microphone set-up or distance. Sound Power data is used by acousticians and engineers to compare devices or to determine the acoustical impact a device or machine will have in a specific environment

Customized Sound Pressure and Sound Power Tests - NOAL can create custom test procedures and specifications to meet the acoustic measurement needs of any specific job or situation

Field Testing


Field Acoustic Testing 

Services by Standard

Accredited ASTM E336 - Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings. ISO/IEC 17025:2017 accredited through A2LA Certificate 4240.01

ASTM E1007 - Standard Test Method for Field Measurement of Tapping Machine Impact Sound Transmission Through Floor-Ceiling Assemblies and Associated Support Structures

ISO 9614 - Acoustics -- Determination of Sound Power Levels of Noise Sources Using Sound Intensity. Part 1: Measurement at discrete points. Part 2: Measurement by scanning. Part 3: Precision Method for measurement by scanning

AHRI Standard 230 - Sound Intensity Testing Procedure for Determining Sound Power of HVAC Equipment

E966 - Field Measurements of Airborne Sound Attenuation of Building Façade and Façade Elements

Field Acoustic Testing 

Services by Type

Field sound power testing of equipment using sound intensity methods

Reverberation Time (RT60) - Measurement of reverberation times (RT60) to diagnose and determine acoustic treatment quantities and placement. Reverberation time (RT60) is the most commonly measured and specified metric for describing room acoustic character

Background Noise / Noise Criteria - Measurement of background noise levels for determination of Noise Criteria (NC) and other mechanical and background noise-related ratings.  NC is the most common metric for describing the background noise levels in an architectural space

Building Facades - Measurement of building facades and roof/ceiling structures for sound transmission loss. Provide Outdoor Indoor Transmission Class (OITC) ratings

Sound and Structural Flanking Investigations - Use advanced techniques to diagnose sound transmission problems and flanking paths in buildings.

Environmental Noise Studies – Whether for compliance with community noise regulations or for environmental impact or suitability studies, NOAL can design and implement an on-site environmental acoustical measurement. Typically, environmental acoustic evaluation includes the measurement of statistical noise levels such as L10, L50 and L90

Studio Acoustics /
Audio Systems Field Testing
Services by Type

Frequency Response – Measure and tune rooms and/or audio systems for optimized response. Systems for Auditoria for music or speech can be optimized for response.  Studio control rooms can be adjusted with broad or tuned absorbers, diffusion and proper monitor / listener arrangements

Speech Intelligibility - Measure and diagnose multiple room acoustic parameters including Speech Transmission Index (STI), Rapid Speech Transmission Index (RASTI), Articulation Loss of Consonants (%ALONS), and Clarity (C50)

Research, Consulting, Design


Noise Isolation Design 

and Remediation

Whether its designing a room from scratch, or diagnosing and providing remedies for existing rooms, NOAL has the tools and knowledge to provide state-of-the-art airborne and structure-borne isolation diagnostics and designs. Decades of experience with real-world problems and solutions for clients and architects. Common consulting and design areas include multi-housing units, incompatible commercial adjacencies, machine or mechanical room isolation, and manufacturing facility noise, etc.

Room Acoustic Design 

and Remediation

Whether the room exists (yet) or not, NOAL is capable of modeling room acoustics and providing recommendations for room dimensions and shapes, as well as exact finishes, treatment types and locations to provide an optimized acoustic experience in line with the use of the space. From small studio control rooms to meeting rooms, lecture rooms and large concert halls, NOAL is equipped to provide the required acoustic design expertise to ensure the success of the project.

HVAC Noise and Rooftop Equipment Noise

Measurement and diagnosis of HVAC noise and vibration, its effect on room noise (Noise Criteria or NC). Also capable of measuring in-situ sound power of roof-top equipment or measuring and remediating environmental noise levels at adjacent properties or areas.

Audio System Design

NOAL staff has decades of experience designing, specifying and using audio systems of all sizes and types. High-quality, high-intelligibility system designs for meeting rooms, sanctuaries, convention centers and auditoria. As musicians on the side, we have the unique advantage of encountering all sides of the acoustic and audio system experience.