Understanding Wind Noise

Wind noise is a complex phenomenon spanning aerodynamics, acoustics, and the physiology of human hearing. The amount of noise generated depends on factors like 1) speed, 2) riding position, 3) turbulence, and so on. At moderate cycling speeds, wind noise can impact the ability to hear surrounding sounds.

Understanding the complexities of Ear-Wind noise requires specialized testing / analysis.

10 to 35 mph wind noise measurements - with both in-canal and outside microphones.

Measuring and mapping wind noise - different directions, velocities, and turbulence levels.

Turbulence intensity (TI), fast Fourier transform (FFT), and power spectral density (PSD) analysis.

Flow visualization with simultaneous wind noise audio and turbulence related (TI) data capture.

Pressure measurements with a GRAS 48LX-1 ultra-thin (1mm) precision surface mounted sensor.

KURZ 493 hot wire anemometer (velocity / turbulence intensity) and differential pressure manometer.

"Turbulent airflow, characterized by a '-5/3 power law' energy distribution across its constituent eddies, is a root cause of cycling wind noise. This turbulent flow generates pressure fluctuations across a range of frequencies, which interact with the ear. Kolmogorov's '-5/3 law' dictates how energy is distributed, influencing the intensity and spectral content of cycling wind noise." [RW]

Understanding wind noise helps us develop the most effective products.