How Cat-Ears Work
"I cannot say enough good things about this product... and my
elation at an ingenious solution to a heretofore unsolved dilemma."
(P. Finley - Adventure Cycling Association)
Wind Noise is a complex phenomenon spanning aerodynamics, acoustics, and the physiology of human hearing. It can easily exceed 85 dB at moderate cycling speeds - altering your hearing threshold, masking surrounding sounds like approaching cars, and adversely impacting your situational awareness. The actual amount experienced depends on numerous factors like: 1) cycling speed, 2) riding position, 3) head shape, 4) wind turbulence, and so on...
Cat-Ears products dampen / dissipate energy from the wind because the materials add light resistance to turbulent flow. It makes the shear layer gentle and causes the maximum turbulent region move farther away away. They also reduce the maximum turbulent intensity - reducing vortex shedding (flow resistance attenuates vortex motion and reduces the acceleration of vortices). They are also engineered to enable ‘controlled porosity’ – i.e. the material allows a diffused flow of wind to pass through to the leeward (ear) side. As a result the problem of high speed turbulence is further reduced and the effective wind reduction area is expanded.
Cat-Ears products are designed to:
> Dampen / decrease wind velocity
> Dissipate / diffuse wind energy
> Deflect / disperse wind flow
Without 'blocking' surrounding sounds
To reduce the most wind noise, one needs to match acoustic material(s) to the specific characteristics of the oncoming wind. What’s more, the product’s final shape can affect the performance of its materials. Effectiveness depends on both the internal structure and on the overall shape, or external structure. A precise understanding of the aero-acoustic characteristics, such as the performance at various frequencies / flow characteristics, is essential.
Cat-Ears are the most exhaustively tested products of their kind on the market. We don't make extraordinary claims based on measurements that don't correspond to the wind noise and perceived wind noise reductions experienced by cyclists. We invite you to read about Cat-Ears testing and compare it to testing performed by any other company.
Drag and Resistance coefficients are important when designing effective wind noise reduction products.
Designed Flow Resistance
Makes the shear layer gentle
Reduces the turbulent intensity
Reduces acceleration of vortices
Make the maximum turbulent region
move apart from the product (and ear)
Attenuate wind noise producing pressure
fluctuations (...known as pseudo sound)
Safer Cycling Through Sound Engineering