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Sound Power & Source Ranking

Panel Noise Contribution

PNC | Panel Noise Contribution | Detailed acoustic analysis of a vehicle interior​

The Microflown PU-based Panel Noise Contribution is a very fast and accurate method to measure and analyse sound source locations and their contributions. The method is a well-known methodology for an airborne Transfer Path Analysis (TPA) in an interior.


  • Typical frequency range 40Hz - 5000Hz
  • Fast method (full car in 1 day)
  • High spatial resolution, typically over 100 panels
  • Flexible: scattered array suitable for any vehicle interior
  • Spatial distribution of sound pressure, acoustic particle velocity and sound pressure contribution


  • Acoustic optimization of vehicle interior
  • Sound package optimization
  • Damping optimization
  • Troubleshooting

PU Array based PNC solution

Pressure contribution from individual panels towards a reference point can be accurately calculated. A set of PU probes are used for measuring local source strengths and transfer functions (with reciprocal measurements). Thanks to the physical advantages of measuring sound pressure and particle velocity directly, there is no need for acoustic treatment of the interior under test.

Measurement methodology

Three steps are required to perform the panel noise contribution analysis:

1. Positioning: the probes are attached to the vehicle interior surfaces (doors, headliner, dashboard, etc.)

2. Source strength: this step is performed while the vehicle is operational, either in a laboratory or while driving on the road. The source strengths are determined by measuring the acoustic particle velocity close to the panel surfaces.

3. Transfer path: this step is done reciprocally by using a volume velocity source.

The individual panel contributions are then calculated towards a specific reference point by combining the data. In a car interior this would typically be the drivers‘ ear.

Scanning Solution: Scan&Paint TPA

An advanced version of the traditional Scan & Paint 2D, called Scan & Paint TPA, is also a solution for airborne transfer path analysis (TPA). Panel Noise Contribution can then be also calculated provided that the sound field is stationary during operational conditions. This solution relies on the operator to preserve the probe distance and orientation constant during the measurements but it leads to higher spatial resolution results than traditional array based systems. The overall measurement time for characterizing an entire car is also very fast, a full vehicle interior can be characterized in 1 day.