ASTM E90 Standard Test Method for Airborne Sound Transmission Loss of Building Partitions and Elements

The standard "ASTM E90 Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements" developed by the American Society for Testing and Materials (ASTM) describes a test method for laboratory measurement of airborne sound transmission loss of building partitions such as all types of walls, movable partitions, floor-ceiling assemblies, doors, windows, roofs, panels and other space dividing elements.

Laboratories are designed so that the test sample forms the primary sound transmission path between the two test rooms, creating approximately diffuse sound fields within the rooms. The requirements for accrediting a laboratory to perform this test method are included in the annex to the standard (Annex A4).

Sound transmission loss, as defined in ASTM C634, refers to the response of specimens exposed to a diffuse incident sound field and is the basis for this test method. Therefore, the test results are directly related to the performance of similar specimens exposed to similar sound fields. However, it provides a useful overall measure of performance across the various sound fields to which a partition or element may typically be exposed.

In laboratories designed to meet the requirements of this test method, the only significant path for sound transmission between rooms is through the test sample. This is generally not the case in buildings where there are many other paths for sound transmission (sideways sound transmission). Consequently, sound ratings obtained using this test method do not directly correlate to sound insulation in buildings; they represent the upper limit of what would be measured in a field test.

This test method is not intended for field testing. The test method described in ASTM E336 applies to field testing. The comparable quantity measured using the ASTM E336 test method is called apparent sound transmission loss due to the presence of sideways sound transmission.

Laboratory sound transmission loss refers to the measured reduction in sound energy as it passes through a structural element such as a wall, floor, ceiling, door, or window in a controlled laboratory environment. Sound transmission loss is the difference in sound pressure levels (in decibels) between the source (where the sound originates) and the receiver (where the sound is measured) after sound passes through a test sample. Laboratory sound transmission loss measurements are performed in specialized acoustic test chambers. The environment is carefully controlled to eliminate external noise and ensure accurate measurements.

The purpose of the ASTM E90 standard is to evaluate and compare the acoustic performance of materials or assemblies. It is often used to calculate sound transmission class ratings, which are single-number ratings that simplify performance interpretation.

Laboratory sound transmission loss represents the product's ideal performance under standardized conditions. However, field sound transmission loss includes real-world variables such as installation imperfections, side paths, and construction tolerances and is measured in the field using ASTM E336 or ISO 16283-1 standards.

The ASTM E90 standard test method is commonly used in architectural acoustics, product development (e.g., for window, door, and wall manufacturers), building code compliance, and acoustical engineering and noise control. For companies working specifically with soundproofing, construction, or acoustical materials, the ASTM E90 standard provides a fundamental method for understanding and comparing the sound performance of different building systems.

Loss of sound transmission is considered important for the following reasons:

• Privacy: In residences, hospitals, offices, and hotels, sound transmission loss ensures speech privacy, preventing conversations from being heard through walls or doors. This supports confidentiality in legal, medical, and institutional settings.
• Comfort: In residential buildings, good sound transmission helps block out external noise (e.g., traffic, neighbors) and internal noise (e.g., plumbing, appliances), contributing to quiet, relaxing environments.
• Productivity and focus: In workplaces and schools, reducing noise distractions from adjacent rooms or hallways improves concentration and performance. This is especially critical in open-plan offices, call centers, and coworking spaces.
• Health and well-being: Chronic noise exposure has been linked to stress, sleep disturbances, and even cardiovascular problems. Sound transmission loss helps maintain acoustic environments that support mental and physical health.
• Acoustic design: Sound transmission loss data helps architects and engineers select and specify materials that meet acoustic performance objectives. This requirement is essential in recording studios, performance spaces, and home theaters.
• Building code and certification compliance: Many national and international standards require minimum sound transmission loss and sound transmission class performance levels for specific building types or areas. Sound transmission loss measurements in accordance with ASTM E90 provide the objective data needed for compliance and certification.

In short, sound transmission loss is a critical requirement wherever noise control or speech privacy are important. Measuring it enables informed decisions in architecture, product design, urban planning, and health-focused building strategies.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, boasts a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the ASTM E90 Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions and Elements.