According to a study conducted at Antwerp University Hospital in Belgium, one in five high school students have permanent ringing in the ears. Three in four students reported temporary episodes of tinnitus. The implications of these findings are important. Tinnitus is typically caused by repeated exposure to loud noise. It is no coincidence then that nearly 90% of people with tinnitus also have a hearing loss. Therefore, the sources of repeated loud noise exposure for teenagers (such as personal listening devices) must be identified. Dr. Roland Eavey, an ear, nose and throat specialist at Vanderbilt University in Nashville, Tennessee, believes this information can be used to help teenagers understand the potential risks of hearing loss and personal listening devices. He states: "Hearing loss from noise used to be from external sources such as loud industry and the military... Nowadays the loud volume is from self-inflicted sources such as personal listening devices... Perhaps [the presence tinnitus] might be like warning smokers to heed the cough before lung cancer is found..."
The individual must also be educated on safe listening volumes and sound protection. Over-the-ear headphones usually block out surrounding noises better than ear buds and allow the individual to listen to music at lower volumes. Also, the volume level of most personal listening devices can be limited to a safe listening level. Limiting the volume to 80% of it's maximum level is generally a good guideline. An individual should be safe listening to volumes of 85-90 dBs for a period of 90-120 minutes per day.
For more information on this research and the source of this blog post, click here.
Researchers at Princeton University have created a fully-functional "bionic" ear. Using a 3D printer, scientists have created an ear that hears radio frequencies a million times higher than the human ear. Michael McAlpine, lead researcher on the project, had this to say about its purpose: 
