Tailor Made Notched Music Therapy (TMNMT) – The scientifically proven auditory neuromodulation treatment for tonal tinnitus.

Tinnitus is a phantom sensation. It may be considered the conscious expression of an apparent sound that originates in an involuntary manner in the head of its owner (1). Because of this, tinnitus is not a disease but a symptom that derives from a series of underlying causes. The most prominent of these is noise-induced hearing loss. The prevalence of tinnitus is especially high in industrialized countries and may affect up to 15% of the general population. The perception of tinnitus can take many forms: whistling, beeping, hissing, pulsing, ringing… etc. However, in almost 70% of tinnitus patients, it sounds like ringing, chirping, hissing, whistling, a musical note, or a steam whistle. We call this general tonal tinnitus.

Today we know that tinnitus is a malfunction of the human auditory cortex, and, in most cases, it is triggered by injuries of the sensory organ, the cochlea. For example, in a normally functioning auditory cortex, when we perceive a 2 kHz tone, the excitatory neurons coding 2 kHz get activated, while inhibitory neurons also get excited spreading lateral inhibition to the neighboring neurons on the next level of auditory processing (2). As long as excitation and inhibition are in balance, normal functioning is guaranteed. But what happens after injury of the inner hair cells of the cochlea? The result is reduced activation in the auditory nerve and subsequently a reduced input to the auditory cortex. This is followed by a loss of excitation and, more importantly, by loss of inhibition of the neurons coding the region affected by the hearing loss. Since our brain is plastic, it triggers adjustments in the auditory cortex. The cortical neurons are “rewired”, which culminates in maladaptive functional reorganization of cortical structures. Neurons coding the frequencies close to the region of hearing loss become over-represented and hyperactive. This hyperactivity resembles the tinnitus noise perceived without any external sound source. While the neural generators of tinnitus are primarily auditory cortical areas, non-auditory brain regions also play a crucial role resulting in maladaptive attention towards the tinnitus as well as a negative emotional response. This working model of tinnitus has been proven by a series of peer-reviewed publications (see the list under "Publications”).

IF the tinnitus, as illustrated in our working model, is a result of hyperactivity of auditory neurons coding the tinnitus frequency and has developed over time due to the lack of inhibition…

THEN it is logical to believe we can reduce tinnitus perception by introducing inhibition onto the over-activated neurons representing the tinnitus frequency. Thus, removing exactly these frequencies from a complex auditory stimulus will cause the brain to reorganize around regions coding the tinnitus frequency. And so, this neuromodulatory driven treatment of tonal tinnitus is based on the neurophysiological effect of inhibition-induced brain plasticity.

This is the foundation for developing a novel sound treatment for tonal tinnitus, the tailor made notched music therapy (TMNMT), which has been developed and evaluated in a series of studies over the last 5 years. Over the course of several months, for one to two hours per day, tinnitus patients attentively listened to music from which the spectral energy band around their individual tinnitus frequency had been removed by applying a digital notch filter in real time. While the cortical neurons coding the tinnitus frequency would get minimal to no acoustic input from the notched music, the neighboring neurons would be fully activated. Consequently, the over-activated neurons coding the tinnitus frequency are inhibited by neurons coding the frequencies around the notch (3,4,5,6).

Please note: the tailor-made notched music approach is not a musical treatment of tinnitus per se. Instead, it promotes a scientifically validated, inhibition-induced brain plasticity effect on those cortical neurons generating the tinnitus perception. This effect can cause a significant reduction in cortical tinnitus hyperactivity, followed by reduction of the tinnitus loudness and tinnitus-related emotional distress. Furthermore, the more one listens to the therapeutic music, the stronger and more lasting the effect.

Our approach utilizes the individual’s own music for two reasons: (1) music has a sufficiently wide energy spectrum, including the tinnitus frequency, to act as an acoustic carrier for the therapy; and (2) we use the strong impact of music on positive cortical plasticity modulations. Since music is enjoyable and able to focus attention for a long time, it efficiently supports those cortical plasticity changes that inhibit and normalize the maladaptive tinnitus network.