Measurements | Acoustic Comfort: Interior Noise

Acoustic Comfort: Interior Noise

To investigate the acoustic field inside the car passenger compartment, the Pininfarina Wind Tunnel is equipped with the following instrumentation:

  • Microphones,
  • Acoustic Dummies,
  • Spherical Array.

The microphones are better suited to pick up local infiltration noise, to detect possible defects existing in the sealing system of doors, side windows, to measure the noise in a specific point of interest, etc.

Acoustic Dummies (see fig.) are better suited to measure overall noise in the passenger compartment. The dummy is equipped with 2 equalized microphones in order to simulate the human ears. In figs. 2,3,4 some typical results are reported





Example of results



Example of narrow band analysis of a measure acquired by the left ear of the acoustic dummy placed on the driver’s seat.





Example of 1/3 octave band analysis of a measure acquired by the left ear of the acoustic dummy placed on the driver’s seat.





Analysis of the noise variation as function of the velocity

In addition to the information of the overall internal noise, it is possible to localize the sources inside the car compartment by using the spherical array (see fig. under). The signals acquired by the microphone array are processed with a “Spherical Beamforming” algorithm. The sphere is also equipped with 12 cameras. Plotting the obtained results on the images acquired by the cameras it is possible to localize the sources which contribute to the car internal noise.