| | Category | EMNC | P13 | Wind Noise Reduction Device for the Hearing Impaired |
| | Abstract | The research goal was to provide a device that reduces discomfort due |
| | to wind noise experienced by hearing aid users while riding a bike. The |
| | device reduced the noise while allowing important surrounding |
| | background sound such as cars, sirens, and other motor vehicles to be |
| | heard. Three testing methods were configured; a bike rig with a false |
| | head and a microphone in the ear, a wind tunnel with a microphone in a |
| | false ear, and finally a wind tunnel where the microphone was placed |
| | above the ear, as it exists in behind-the-ear (BTE) hearing aids. The |
| | third method was then used to draw data, results, and conclusions |
| | from, as the first two failed at producing conclusive results. Sound was |
| | recorded for a minute for each combination of test parameters. Each |
| | test condition was repeated with a whistle noise to replicate an |
| | emergency vehicle siren. Various materials were then used to block |
| | sound but still allow for the siren-noise replica to pass through. These |
| | included: a control group with nothing blocking the ear, blue high |
| | density foam, a replica of a preexisting product Cat Ears, kitchen |
| | sponge foam, and speaker foam. Three fan speeds were also used: |
| | low, medium, and high. The head was oriented at three angles: forward, |
| | toward the ear (left), and away from the ear (right). An open-source |
| | program, Audacity, was used to analyze decibels as a function of time, |
| | and then decibels as a function of frequencies (hertz). These were |
| | plotted based on the microphone’s reference sound and then replotted |
| | on the a-weighted curve of human hearing. There was no difference |
| | found in the left and right facing data, so that was disregarded when |
| | analyzing and only front-facing data was used. Though all materials |
| | were effective to some extent, it was determined that the speaker foam |
| | worked the best across all three fan speeds allowing for necessary |
| | sounds to pass through but blocking wind noise. The control group with |
| | nothing blocking the ear performed the worst. The research goal was |
| | met due to the success of the materials used in reducing air turbulence |
| | around the microphone. |
| | Bibliography | http://www.cat-ears.com/how-they- |
| | workhttp://www.phys.uconn.edu/~gibson/Notes/Section5_2/Sec5_2.htm |