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To narrow the band width of these resonators there is a degree of positive feedback in each and it is believed that tinnitus occurs when the degree of feedback gets out of control and oscillation occurs.
If a microphone is placed in the ear of a tinnitus sufferer the sound generated by the oscillating resonators can be heard
I'm sceptical. To sustain oscillation at a constant amplitude, a loop gain of exactly unity is required. Exactly as in ±nothing.
Quote from: vhfpmrI'm sceptical. To sustain oscillation at a constant amplitude, a loop gain of exactly unity is required. Exactly as in ±nothing.This is true if you wish to produce a pure sinusoid with a linear circuit.However, the ear is rather non-linear, and the response of nerves is rather non-linear.
In the case of spontaneous otoacoustic emission, the frequency appears fairly stable, but the measured amplitude varies randomly over a wide range (a factor of 10,000:1)- it seems to be a chaotic oscillator rather than a linear oscillator.But the majority of tinnitus appears to be neurological, generated in the nerves and/or brain.Neurones that are not stimulated for some time (eg due to frequency-selective hearing loss) could increase their sensitivity in a futile attempt to extract some signal, and could produce spurious sensations of sound. Or they could make cross-connections with other nerves that seem to be doing more interesting things. The formation and maintenance of synapses to produce learning and useful information processing is a bit of a mystery in brain studies. As are the processes when this goes awry.