Moreover, the risk of hearing damage from headphones is higher than with loudspeakers, even at comparable volumes, due to the close coupling of the transducers to the ears. One of the benefits of headphone listening is the ability to detect musical details. Any hearing damage would have substantial impact on that experience. This article takes a look at the process of human hearing and offers guidelines for safe listening. The simplified view of the human ear in figure 1 identifies the basic mechanisms of human hearing.
Sound travels down the ear canal and causes the eardrum to vibrate.
Inside the middle ear, a bone attached to the eardrum vibrates with the eardrum and propagates sound waves through the middle ear by way of two other ear bones, which amplify the sound. The third ear bone vibrates against the cochlea of the inner ear. The cochlea is filled with fluid and is lined with frequency-sensitive hair cells that convert vibrations into electrical signals going to the brain. The cells that respond to high frequencies are located in the outer cochlea, and those for the low frequencies follow behind. Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.