Tinnitus can arise anywhere along the auditory pathway, from the outer ear through the middle and inner ear to the brain's auditory cortex, where it's thought to be encoded (in a sense, imprinted). One of the most common causes of tinnitus is damage to the hair cells in the cochlea (see "Auditory pathways and tinnitus"). These cells help transform sound waves into nerve signals. If the auditory pathways or circuits in the brain don't receive the signals they're expecting from the cochlea, the brain in effect "turns up the gain" on those pathways in an effort to detect the signal — in much the same way that you turn up the volume on a car radio when you're trying to find a station's signal. The resulting electrical noise takes the form of tinnitus — a sound that is high-pitched if hearing loss is in the high-frequency range and low-pitched if it's in the low-frequency range. This kind of tinnitus resembles phantom limb pain in an amputee — the brain is producing abnormal nerve signals to compensate for missing input.
Before long, you’re both mentally and physically stimulated in ways that make it even harder to relax and fall asleep. Like any other form of anxiety, stress about falling asleep creates mental arousal, bringing your brain to alertness. And it also creates physical arousal, raising heart rate and body temperature. This kind of anxiety can lead to behaviors that further undermine sleep, including:
Once the music package (MP3 player preloaded with assigned music tracks and headphones) was ready, participants were briefed on safe listening levels, and were instructed to complete a weekly log book to record their listening duration and frequency. The algorithms which modified the music provided to participants are built into proprietary software that was developed internally by Sound Options Tinnitus Treatments Inc. The modified and placebo music packages consisted of 4 hours of classical music.