Wind Noise Related Research
Surprisingly, there is a limited amount of research regarding wind noise and the human ear.
(Wind) Noise Heard by Human Beings when Exposed to Atmospheric Winds
U.R. Kristiansen - Acoustics Laboratory, The University of Trondheim, Trondheim, Norway
O.K.Ø.Pettersen - Department of Acoustics, The University of Trondheim, Trondheim, Norway
Abstract: By placing subjects in front of a wind tunnel opening it has been possible to measure the noise heard by human beings exposed to atmospheric winds under controlled conditions. The influence of wind velocity and angle of incidence is shown. Flow visualization and aerodynamic pressure measurements show that the relatively high noise heard when looking directly into a wind has its origin in fluctuations in the wake created by flow separation at about the position of the cheekbone...
"The average person facing a 21 mph wind experiences wind noise at an intensity of 92 dB."
Wind Noise Deflection for the Human Ear - Masters Thesis
Porter Gieske - Master of Industrial Design, School of Design, Pratt Institute, New York
Introduction: On a scientific level, tests on humans have revealed that exposure to low levels of noise for a moderate period of time have resulted in emotional and physical fatigue. Other symptoms that become evident at higher levels of noise exposure are nausea and loss of acute motor skill coordination as well as lower results concerning attention in problems requiring higher concentration. The area of health is directly related to the importance of safety as it relates to (temporary or permanent) hearing damage due to exposure to wind noise...
Bicycling is an increasingly popular sport and the common time duration can be several hours per day, several days per week. Wind noise abatement can be relied upon to raise the rider's level of enjoyment / relaxation as well as enhancing the awareness of dangers surrounding him...
We would like to thank Porter for contacting Cat-Ears and sharing his Masters Thesis with us.
Recent Studies on Wind Noise (Audiology Convention Presentation)
An Instructional Course Presented at the 14th AAA Convention, Philadelphia, PA
Presented by: Stephen C. Thompson, Ph.D., Knowles Electronics, LLC, Itasca, Illinois
Harvey Dillon, Ph.D., National Acoustics Laboratory (NAL), Chatsworth, NSW, Australia
Concluding comments about wind noise:
Wind noise levels can be very intense
Obstacles (e.g. head, pinna, tragus) act as:
1. Wind guards
2. Turbulence sources
3. Turbulence shredders
Large obstacles create low frequency turbulence (head)
Medium obstacles create mid frequency turbulence (pinna)
Smaller obstacles create higher frequency turbulence (tragus)
As wind speed increases, noise increase and frequency spectrum extends upward
Directional patterns produce much higher wind noise than non-directional patterns
Aerodynamics / Aeroacoustics (Wind Noise) of Airflow Over a Human Head
Fuyin Ma, Jiu Hui Wu, Fu Gang, Chang An Bai, School of Mechanical Engineering, XJU / SHT, China
Abstract: Airflow should be affected by ear, nose, etc., and aerodynamic sound could be brought when the human head and the airflow occurs at a relative speed movement. After the speed of airflow reaches a certain speed, due to the strong airflow interference, the aerodynamic noise could be brought, and it could greatly impact the athletes to make action decisions. In this paper, the computational fluid dynamics (CFD) method is used for solving the aerodynamic behavior of a human head under different air velocities, and the pressure on the head surface and the airflow around the head is calculated. Then, the above-mentioned conditions of different aerodynamic sound are solved by the finite element / infinite element method (FEM/IFEM), the points in the canal entrance of the two ears are picked up for collecting the SPL spectral curves, and the sound distribution of the horizontal plane and the median plane are drawn...
Windgeräuschreduktion am Ohr (Wind Noise Reduction at the Ear) - Masterarbeit
Lehrstuhl Technische Akustik, Brandenburgische Technische Universität, Cottbus, Deutschland
Einleitung: Due to the increasing density of road traffic, the mutual perception of road users is becoming increasingly important. However, when the ear is exposed to the wind, as in cycling, it causes turbulence that leads to disturbing wind noise. This noise has a sound pressure level, even at low cycling speeds, which has a strongly concealing effect on traffic noise. For example, the delayed perception of a vehicle approaching from behind represents only one of the safety-relevant situations that are influenced by the phenomenon...
The basic structure was a KEMAR artificial head. This was positioned in the aeroacoustic wind tunnel of BTU Cottbus-Senftenberg in the middle of a round nozzle with a diameter of 35cm. The experiments were carried out at wind speeds of 5, 10, 15, and 20 m/s...
As shown in the experiments, the top and bottom of the ears have a negligible impact on the wind noise. Much more important, the inflow of the cavum concha is due to turbulence arising on the temple and cheekbone... (Google Translation)
We would like to thank Thomas for including Cat-Ears and sharing his Master's Thesis with us.
As noted in the thesis, the final WNR prototype did not outperform our products.
Evaluation of Noise Exposure Secondary to Wind Noise in Cyclists
M. Seidman, MD - Department of Otolaryngology, Florida Hospital, Celebration, Florida
Anna G. Wertz, MD - Department of Otolaryngology, Henry Ford Hospital, Detroit, Michigan
Matthew M. Smith, MD - Department of Pediatric Otolaryngology, CC Hospital , Cincinnati, Ohio
Steven Jacob - Automotive Operations (wind tunnel), Ford Motor Company, Allen Park, Michigan
Objective: Determine if the noise levels of wind exposure experienced by cyclists reach levels that could contribute to noise-induced hearing loss.
Subjects / Methods: A commercial-grade wind tunnel was used to simulate different speeds encountered by a cyclist. A single cyclist was used during the simulation for audiometric measurements. Microphones attached near the ears of the cyclist were used to measure the sound (dB sound pressure level) experienced by the cyclist. Loudness levels were measured with the head positioned at 15-degree increments from 0 degrees to 180 degrees relative to the oncoming wind at different speeds (10-60 mph).
Results: Wind noise ranged from 84.9 dB at 15 mph and increased proportionally with speed to a maximum of 120.3 dB at 60 mph. The maximum of 120.3 dB was measured at the downwind ear when the ear was 90 degrees away from the wind.
Conclusions: Wind noise experienced by a cyclist is proportional to the speed and the directionality of the wind current. Turbulent airflow patterns are observed that contribute to increased sound exposure in the downwind ear. Consideration of ear deflection equipment without compromising sound awareness for cyclists during prolonged rides is advised to avoid potential noise trauma. Future research is warranted and can include long-term studies, including dosimetry measures of the sound and yearly pre-and post-exposure audiograms of cyclists to detect if any hearing loss occurs with long-term cycling.
"Wind noise ranged from 84.9 dB at 15 mph and increased proportionally with speed..."
Understanding wind noise helps us develop the most effective products.