Rising Demand for Vehicle Semi-Anechoic Chambers (VSAC)

The Growing Importance of VSAC in the Automotive Industry

With the rapid shift toward vehicle electrification—including electric vehicles (EVs) and hybrids—the automotive industry is placing greater emphasis on acoustic performance and quietness.
As traditional engine noise disappears, higher-frequency sounds such as motor whine, inverter switching, tire-road interaction, and aerodynamic noise become more pronounced. To ensure product quality and comfort, precise and repeatable acoustic testing is becoming essential.

This has led to the widespread adoption of Vehicle Semi-Anechoic Chambers (VSACs) in the development environments of both automakers and suppliers. A VSAC is a specialized acoustic testing space that combines sound-absorbing walls and ceiling with a hard, reflective floor, allowing vehicles and components to be tested under semi-free-field conditions.

Applications of VSACs in Vehicle Development

VSACs serve as essential tools across all stages of automotive product development. Key applications include:

1. Powertrain Noise and NVH Evaluation

• Testing electric motors, engines, and transmissions for noise and vibration
• Analyzing NVH (Noise, Vibration, Harshness) characteristics
• Measuring acoustic behavior during acceleration and deceleration

2. Tire and Road Noise Testing

• Simulating tire-road interaction using the reflective floor
• Measuring sound power levels in compliance with ISO 3744

3. Interior Acoustic Evaluation

• Assessing cabin acoustic comfort
• Developing speaker systems and active noise cancellation (ANC) technologies

4. Wind Noise Testing

• Combining with wind tunnels for aerodynamic noise assessment
• Measuring wind-induced noise at high speeds

5. EV & Hybrid-Specific Acoustic Testing

• Measuring inverter and electric motor noise
• Evaluating resonance, piezoelectric whine, and charging noise

VSAC Market Trends

Demand for VSACs is growing rapidly in response to several industry shifts:

• ISO 3744 / 3745 Compliance
  Accurate sound power level testing in semi-anechoic or fully anechoic environments is increasingly required by ISO standards.
• Stricter Global Noise Regulations
  Enhanced regulations such as UN-R51.03 and EU mandates are driving the need for external and interior noise testing.
• Autonomous Vehicle Development
  Low-noise environments are critical for the development of ADAS, AVAS, and VSP systems for autonomous and electric vehicles.
• Component-Level Testing by Suppliers
  VSACs are being used not only for whole-vehicle testing, but also for individual component analysis, including motors, gears, and batteries.

HBK × Sonora: Next-Generation VSAC Solutions

HBK and Sonora Technology jointly offer Modular Semi-Anechoic Chambers (MSACs)—a new generation of customizable VSAC solutions engineered for flexibility and performance.

Key Features:

• BFW (Broadband Fractal Wedge) Technology
  Delivers broadband sound absorption across low to high frequencies
  Fully compliant with ISO 3745:2012 measurement requirements
• Modular Design Scalable for Any Vehicle Size
  Supports both passenger cars and large commercial vehicles
  Reduces construction and maintenance costs by optimizing test volume
• Integration with HBK Measurement Systems
  Combines high-precision microphones and data acquisition platforms
  Enables real-time analysis of wind noise, motor whine, and more

Conclusion

As electrification and automation redefine the automotive landscape, Vehicle Semi-Anechoic Chambers are becoming critical infrastructure for acoustic testing and product validation.
HBK and Sonora Technology, through their advanced MSAC offering, provide an ISO-compliant, high-performance solution that meets the evolving needs of today’s vehicle developers.

For companies considering the adoption of a VSAC solution, Moritani Corporation offers comprehensive support—from consultation and system design to installation and after-sales service.

Contact Moritani Corporation today to explore our complete acoustic testing solutions for the automotive industry.

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