NVH Acoustic Test Chambers for Noise, Vibration and Harshness Analysis

Varitone® Sound-absorbing modular panels

Most NVH test chambers are designed as high-absorptive acoustic environments, providing exceptionally low background noise and excellent measurement repeatability without requiring a fully qualified free-field over the entire test volume. By combining Varitone® sound-absorbing panels with Noise-Lock® or Noishield® STC-rated modular panel, the chamber achieves broadband sound absorption and acoustic performance approaching free-field conditions over reflective plane. In most octave bands, the deviation from the inverse-square law is typically only 3–4 dB above the ISO 3745 free-field tolerance, making these chambers an ideal solution for precision NVH development, sound power measurements and automotive component testing. Learn more about simulated free-field.

IAC Acoustics is a global leader in the design and construction of turnkey NVH test facilities. The flexibility of the Microdyne® modular construction system enables the development of highly complex acoustic test chambers for full-vehicle testing as well as large powertrain and subsystem applications. Learn more about Microdyne® technology in our hemi-anechoic chamber solutions or explore our fully anechoic chamber technology.

Each NVH test chambers require specialized acoustic access systems that allow vehicles, powertrains, and large test specimens to enter the facility without compromising its acoustic performance. Acoustic doors, observation windows, and equipment access panels are therefore engineered as integral parts of the chamber enclosure, with door frames, seals, and closures designed to maintain the required sound insulation while matching the geometry and depth of the absorber lining.

Depending on the application, IAC supplies single- and double-leaf acoustic doors, sliding or pivoting vehicle access doors, personnel doors, acoustic windows, and custom service penetrations. Each system is designed to provide reliable operation, long-term sealing performance, and unobstructed access while preserving the low background noise and free-field conditions required for accurate NVH measurements.

Automotive NVH test chambers require carefully engineered HVAC and exhaust noise control systems to maintain stable environmental conditions without affecting acoustic measurements. High-capacity ventilation systems must remove engine heat, supply fresh air, and control temperature, humidity, and airflow while keeping background noise below the chamber's acoustic performance requirements.

IAC designs complete ventilation systems including Quiet-Vent® duct silencers, acoustic air handling units (AHUs), exhaust extraction systems, forced-air cooling ducts, and intelligent control systems. Every intake and exhaust path is acoustically engineered to minimize regenerated noise, allowing full-vehicle and powertrain testing under repeatable operating conditions while preserving the free-field environment inside the chamber.

Automotive NVH test chambers require careful isolation of the chamber structure, reflective floor, and chassis dynamometer system to prevent structure-borne noise and vibration from influencing acoustic measurements. IAC evaluates the site layout, surrounding facilities, dynamometer pit, plant room equipment, and floor slab construction to determine the correct isolation strategy for each project. For more demanding applications, IAC Acousti-Flote™ floating floor systems and spring-mounted concrete slabs can be engineered to reduce vibration transmission while preserving the hard reflective floor surface required for hemi-anechoic and vehicle pass-by measurement conditions.

Dynamometer pits also require engineered ventilation and cooling. Silenced air inlets, pit extract systems, localized cooling ducts, and exhaust ventilation can be integrated to remove heat and fumes while keeping background noise to a minimum during vehicle and powertrain testing.