Chapter 2: What Is Tinnitus?

[Tinnitus Talk]

Suggestions for Chapter 2: What Is Tinnitus?

Put all of your suggestions, comments and ideas in here and we'll update the guide as we go.

The guide can be found here Tinnitus Help: The Guide

The content that goes in the guide will be for everyone. Please consider that this is for people from many different cultures and belief systems - don't be offended if there are certain things that don't make it in

 

[Cityjohn]

As many sources around the world will note, tinnitus is an audible sound that originates from the body itself. In most cases this tinnitus is subjective, meaning that only you can hear it. In few cases it can be heard by others listening closely, this is called objective tinnitus. Both types could be heard as any sound. Even in objective tinnitus high frequency continuous tones are a possibility.
In objective tinnitus there is no hearing damage directly involved with the sound, the sound is simply originating somewhere around the ear, like the whistling sound from blood running through a bendy vane. Subjective tinnitus however is not a sound caused by vibrations in the air, which are then sensed as sound in the ear. Rather subjective tinnitus is noise produced in the auditory nervous system directly without external stimuli.

Every one, and every system, has inherent noise. An electric guitar will produce noise, and the amplifier has an input filter which filters out this noise, leaving you with a clean sounding signal. In subjective tinnitus our human input filtering system has malfunctioned.
The human central nervous system filters noise using many methods. Two main ones are relevant here. Neurons wait for multiple signals on the same line before sending a signal through, a form of confirmation. And the central nervous system seems to wait for a certain proportion of signal before interpreting it as external sound instead of internal noise. The loss of proportionally many neurons that never fire by accident all at once may break the filtering. This could be due to the loss of many synaptic connections along the auditory system, because of acoustic trauma and the associated hearing loss, because of drugs that alter the signaling between neurons and/or permanently damage them, or because of a head injury.

The central nervous system filtering relies on a threshold, because of this tinnitus sufferers will often suddenly get tinnitus, instead of gradually. As the threshold volume of noise is reached you will suddenly start to hear the whole noise produced inside the system at that frequency.
Shown below is a map of the auditory pathway, from the cochlea to the Medial geniculate body an internal noise could be produced that may become audible. The graph shown indicates the pulse that travels through all systems, this data was acquired by means of a BERA (Brainstem Evoked Response Audiometry).

Subjective tinnitus can often be accompanied by other issues such as an over-sensitivity to sound, the experience of pain with or without certain sounds, a sensation of fullness in the ear, weird noises when swallowing, dizziness, etc. These afflictions and tinnitus will have the same cause, or will follow naturally at the advent of tinnitus because the body reacts to tinnitus as if it were an externally produced sound.
It is conventionally thought that a problem with the cochlea or dorsal cochlear nucleus is at the root of most subjective tinnitus in occurrence, simply because these parts are first in line for any damage from the outside world.

There is an extensive source about signal noise in this extended article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2631351/
Two excellent book chapters to read, which help in the understanding of the whole system is: Neuroanatomical Basis of Clinical Neurology 2ed [2014] Chapter 14 & 15

 

[Steve]

As many sources around the world will note, tinnitus is an audible sound that originates from the body itself. In most cases this tinnitus is subjective, meaning that only you can hear it. In few cases it can be heard by others listening closely, this is called objective tinnitus. Both types could be heard as any sound. Even in objective tinnitus high frequency continuous tones are a possibility.
In objective tinnitus there is no hearing damage directly involved with the sound, the sound is simply originating somewhere around the ear, like the whistling sound from blood running through a bendy vane. Subjective tinnitus however is not a sound caused by vibrations in the air, which are then sensed as sound in the ear. Rather subjective tinnitus is noise produced in the auditory nervous system directly without external stimuli.

Every one, and every system, has inherent noise. An electric guitar will produce noise, and the amplifier has an input filter which filters out this noise, leaving you with a clean sounding signal. In subjective tinnitus our human input filtering system has malfunctioned.
The human central nervous system filters noise using many methods. Two main ones are relevant here. Neurons wait for multiple signals on the same line before sending a signal through, a form of confirmation. And the central nervous system seems to wait for a certain proportion of signal before interpreting it as external sound instead of internal noise. The loss of proportionally many neurons that never fire by accident all at once may break the filtering. This could be due to the loss of many synaptic connections along the auditory system, because of acoustic trauma and the associated hearing loss, because of drugs that alter the signaling between neurons and/or permanently damage them, or because of a head injury.

The central nervous system filtering relies on a threshold, because of this tinnitus sufferers will often suddenly get tinnitus, instead of gradually. As the threshold volume of noise is reached you will suddenly start to hear the whole noise produced inside the system at that frequency.
Shown below is a map of the auditory pathway, from the cochlea to the Medial geniculate body an internal noise could be produced that may become audible. The graph shown indicates the pulse that travels through all systems, this data was acquired by means of a BERA (Brainstem Evoked Response Audiometry).

Subjective tinnitus can often be accompanied by other issues such as an over-sensitivity to sound, the experience of pain with or without certain sounds, a sensation of fullness in the ear, weird noises when swallowing, dizziness, etc. These afflictions and tinnitus will have the same cause, or will follow naturally at the advent of tinnitus because the body reacts to tinnitus as if it were an externally produced sound.
It is conventionally thought that a problem with the cochlea or dorsal cochlear nucleus is at the root of most subjective tinnitus in occurrence, simply because these parts are first in line for any damage from the outside world.

There is an extensive source about signal noise in this extended article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2631351/
Two excellent book chapters to read, which help in the understanding of the whole system is: Neuroanatomical Basis of Clinical Neurology 2ed [2014] Chapter 14 & 15

View attachment 10461

Excellent.

For the moment I've pasted it as is but I may make some changes for the casual reader, possibly an easy to understand summary section above and then the more technical text underneath

 

[Kyxwz]

I have different ideas but for me speak in english it's not so easy (for now); and i must to take my life back (college, music, writing, work...) after fourth months from the beginning of hell. So i don't have a lot of time by now but i will try to cooperate.
I attach Susan Shore's reviews that could be have some positive steps on Tinnitus and how probably work when it becomes chronic.

 

[The Red Viper]

This short vid will provide some background on the auditory system:



Some experts believe that hair cells inside the cochlea become damaged, and the brain substitutes a "phantom noise" for the sound frequencies that were once mediated by now-damaged hair cells. Hair cells typically become damaged from loud noise exposure, although they can also become damaged chemically from drugs such as antibiotics and pain relievers.

Finally, this vid provides an in-depth look at the hair cells:

 

[Starthrower]

Excellent post by Cityjohn. Some people state that there must be an EXACT two sentence type of definition for tinnitus or else there can never ever be effective research for it. I disagree. With tinnitus such a "definition" would box the efforts to find a good treatment or a cure for this ailment.

Tinnitus is pretty much an individual experience. And such experiences are numerous and different with regards to severity and how a person eventually copes with the intrusive noise in the brain.

Back in 2002 I had never heard the term before. I had no idea what "it" was. No one ever really spoke about "it" or if they did the message was not heard. What a journey I had.

Even now when I mention it to some non-tinnitus people react as if it is not a big deal thing. Get over it. Don't talk about it. I hear how in the world is this a big deal you must be weak to be taken down because of some noise in the brain.

This places a stigma on the tinnitus person. Reduces self-esteem. And they often become recluses in their own homes and remain silent about the severity of the condition which can bring extreme anxiety, lack of sleep and different levels of depression.

I think the message though is becoming more in the main stream because of Tinnitus Talk's efforts with a support board and Tinnitus Hub.

There is also a program called Dangerous Decibels created by Dr. Billy Martin formally of OHSU and now at the University of Singapore. I was able to attend a few of his presentations to grade school and high school students.

So What Is Tinnitus is and can provide clarity.