Hearing is Believing


With a number of comments received so far on the posts from the European testing being conducted by the National CP Tech Center, it seemed appropriate to fulfill another (quite logical) human sense… hearing.

From the results posted so far, 7 sound clips have been prepared to form a “listening experience” of some of the European pavements: 3 from Austria, 2 from Belgium, and 2 from the Netherlands.

Total OBSI levels and corresponding third-octave spectra from these sections are summarized together below (click on either image to expand):

Graph of third-octave spectra Graph of OBSI levels

Each sound clip was prepared by sampling approximately 5 seconds of OBSI data. The left channel (ear) is a measurement taken near the leading edge (front) of the test tire. The right ear will hear a measurement from the trailing edge (rear) of the tire. Some filtering has been performed to better reproduce the sound as one might hear it at these locations (and still minimizing the effect of wind noise).

To listen to these sound clips, simply click on the following links. If they do not play, you might need to download them first, and play them separately.

File AT03.mp3 (Austria, 8 mm Exposed Aggregate, 7 yrs old)

File AT05.mp3 (Austria, 11mm Exposed Aggregate, 6 yrs old)

File AT06.mp3 (Austria, 8 mm Exposed Aggregate, 15 yrs old)

File BE02.mpg (Belgium, 20 mm Exposed Aggregate, age TBD)

File BE03.mpg (Belgium, 6.3 mm Exposed Aggregate, age TBD)

File NL01.mpg (Netherlands, 8 mm Exposed Aggregate, 1.5 yrs old)

File NL02.mpg (Netherlands, Porous Concrete, 1.5 yrs old)

Don’t forget to load them up on your iPod for maximum enjoyment!!!!