Several patients who are tech-savvy and/or very current on audio have noticed the recent popularity of noise-cancelling headphones. These are very popular, not only for travellers, but anyone who seeks to hear music or recorded books or movies with less intrusive background noise. A patient recently asked if this concept could be used to modify or reduce tinnitus, the phantom noise many patients hear.
The underlying idea behind noise-cancelling technology is that sound is comprised of “condensations and rarefactions” of matter (usually air) in a wave pattern radiating outward from the source. The source may be vocal cords, a stereo speaker, a guitar string or any collision of matter vigorous enough to produce such a disturbance and wave propagation. Sounds are comprised of “sine waves” in various combinations. Waves have the properties of amplitude, which contributes to the strength or intensity of the sound, frequency, which relates to the pitch of the sound (say bass vs. treble), and phase, which describes the pattern of peaks and valleys of any wave. Phase cancellation is a process of generating a sound of identical frequency and amplitude of the incoming sound, but with opposite phase, which is to say, a peak in the incoming sound would be matched in time by a valley in the generated sound. Simultaneous peaks and valleys “cancel out”, leaving very little amplitude (strength) of the wave in question.
While it would be adventageous to be able to apply this idea to tinnitus, we must remember that tinnitus is not an acoustic signal. This phantom perception of a sound is generated along the nerve itself. Nerves carry impulses, also known as spikes towards the brain for recognition, but the signals do not have “phase” in the acoustical sense. Phase cancellation simply would not be effective on the strength of a tinnitus signal travelling towards the auditory portion of the brain.
We would love to explain strategies, based similarly in science, technology and physiology, which HAVE been found to be effective in treating tinnitus. Let us put you on a clear path to good hearing and health.