How Notched Sound Therapy Works for Tinnitus Relief

Notched sound therapy is one of the most rigorously studied non-invasive approaches to tinnitus management. Unlike masking (which simply drowns out the ringing), notched therapy actively targets the neural mechanisms that generate the phantom sound. This guide explains the science, the evidence, and exactly how to use it.

What is Notched Sound Therapy?

Notched sound therapy — also called Tailor-Made Notched Music Therapy (TMNMT) or notched noise therapy — works by removing (notching) a narrow frequency band from a broadband sound signal. The removed band is centred precisely on your tinnitus frequency.

If your tinnitus is a 7,000 Hz tone, a notched noise signal has everything except the frequencies immediately around 7,000 Hz. You hear a broad "shush" sound with a subtle absence at your tinnitus pitch.

Crucially, this is not masking. The signal is not designed to cover up the tinnitus — in fact, for many protocols the notched sound is played quietly enough that the tinnitus remains audible during the session. The therapeutic mechanism is entirely different, and understanding it explains why consistent daily use matters more than session intensity.

The Neuroscience: Lateral Inhibition

To understand notched therapy, you need to understand one principle: lateral inhibition.

In the healthy auditory cortex, neurons tuned to a specific frequency are actively suppressed by neighbouring neurons tuned to adjacent frequencies. This is the mechanism that sharpens frequency discrimination — it's why you can hear the difference between a 7,000 Hz tone and a 7,500 Hz tone.

In many forms of tinnitus — particularly those associated with high-frequency hearing loss — this lateral inhibition breaks down at the tinnitus frequency. The neurons tuned to the tinnitus pitch begin firing spontaneously and persistently, without any external sound triggering them. Adjacent neurons, which would normally suppress this activity, have reduced input because the corresponding frequencies are underrepresented in the sound reaching the ear.

How notching restores inhibition

By playing a broadband signal that contains strong energy at the frequencies immediately surrounding your tinnitus pitch — but nothing at the tinnitus pitch itself — you drive the neighbouring neurons strongly while withholding input to the neurons at the tinnitus frequency.

This is the optimal pattern for lateral inhibition. The active neighbouring neurons suppress the spontaneous firing at the tinnitus frequency. With sustained, regular stimulation over weeks, this reduces the long-term neural gain at that frequency — the brain's internal "volume control" for that pitch gradually turns down.

Clinical Evidence: What the Trials Show

Notched sound therapy is among the best-evidenced non-pharmacological approaches to tinnitus, with multiple randomised controlled trials published in peer-reviewed journals since 2010.

Key studies

• Okamoto et al. (2010) — PNAS: The seminal RCT. Patients listening to notched music (their own playlist with the tinnitus frequency removed) for 12 months showed significantly reduced tinnitus loudness and cortical excitability compared to a sham group. The effect was frequency-specific — only the notched frequency showed reduced neural activity.
• Pantev et al. (2012) — Frontiers in Systems Neuroscience: Confirmed the frequency-specific cortical changes and showed that the effect persisted for at least 6 months after treatment ended in responders.
• Teismann et al. (2011) — PLOS ONE: Demonstrated that even 5 minutes of notched noise exposure produced measurable reductions in cortical activity at the tinnitus frequency — providing a mechanistic basis for the long-term studies.
• Multiple meta-analyses (2018–2024): Broadly confirm a modest but statistically significant reduction in tinnitus loudness and distress. Effect sizes are typically small-to-moderate; individual response varies considerably.

Limitations

It is important to be honest about what the evidence does and does not show:

• Not everyone responds. Responder rates in trials range from 40–70% depending on the study and outcome measure used.
• Most studies show reductions in tinnitus loudness and distress, not complete elimination.
• Optimal session duration, notch width, and sound type are still being researched. Current consensus: 30–90 minutes daily for at least 3 months.
• The evidence is weaker for tinnitus not associated with high-frequency hearing loss (e.g. low-frequency tinnitus).

Finding the Right Frequency — Why Precision Matters

The effectiveness of notched therapy depends heavily on accurately identifying your tinnitus frequency. A 2014 analysis by Reavis et al. found that frequency errors of more than 0.5 octaves significantly reduced the inhibitory effect. If your tinnitus is at 7,000 Hz and you target 9,000 Hz, you may see little benefit.

The pitch-matching challenge

Tinnitus pitch matching is harder than it sounds. Most people can accurately match a tone to within 1–2 semitones on a first attempt, but:

• Tinnitus can fluctuate slightly day-to-day.
• The "octave confusion" problem — many people match one octave below their actual tinnitus frequency because adjacent octaves can sound similar.
• The audiometric "dead zone" at the tinnitus frequency (the area of most hearing loss) can make the tone harder to hear near the tinnitus pitch.

Practical calibration approach

The Tinnitus Wizard app uses a step-by-step pitch calibration process: starting with a wide sweep, then progressively narrowing the range using a forced-choice comparison between the test tone and your tinnitus. This is based on the Müller-Wehlau method and typically takes 5–10 minutes to complete.

How to Use Notched Sound Therapy Effectively

Session structure

• Duration: 30–90 minutes per session. Most clinical trials used 1–2 hours daily. More is not necessarily better — there appears to be a ceiling effect and some evidence that very long sessions may increase fatigue and reduce attention, which affects cortical plasticity.
• Volume: The notched sound should be audible but comfortable — typically 10–20 dB above your hearing threshold, not loud enough to cause strain. Many people find a quiet background level works well.
• Attention: You don't need to actively focus on the sound — you can read, work, or rest. However, complete inattention (e.g., sleeping) may reduce the benefit.
• Consistency: Daily use for at least 10–12 weeks before assessing response. This is the minimum timeframe in which cortical changes are measurable in the literature.

What to expect during sessions

Many people notice that their tinnitus temporarily seems louder or more salient when they first start notched therapy — this is normal and typically settles within 2–3 weeks. Some people experience a brief period of "residual inhibition" immediately after sessions (temporary reduction in tinnitus loudness), which is a positive indicator of neural responsiveness.

Realistic Expectations

Being honest about what notched sound therapy can and cannot do is important.

• Most likely outcomes: Gradual reduction in tinnitus loudness (measured in dB) and/or perceived intrusiveness over 3–12 months. Many responders report the tinnitus becoming "easier to ignore" rather than disappearing.
• Best case: Substantial reduction in tinnitus loudness, reduced distress, improved sleep and concentration.
• Realistic case: Modest improvement in tinnitus loudness with meaningful improvement in quality of life due to habituation and reduced reactivity.
• Non-response: Approximately 30–60% of people do not see significant audiometric improvement. This does not necessarily mean no benefit — reduced anxiety and improved coping are often reported even in "non-responders."

Notched Noise vs Notched Music

The original research by Okamoto et al. used notched music — each participant's own playlist with the tinnitus frequency removed from all tracks. Subsequent studies have also examined notched pink noise, which is what Tinnitus Wizard uses by default.

Pink noise advantages

• Consistent spectral shape across all sessions — easier to control the notch parameters precisely.
• No content distraction — allows focus during work or reading.
• More consistent inhibitory stimulus across the frequency spectrum.

Notched music advantages

• May improve compliance for some people (more pleasant for long sessions).
• Some evidence it may be slightly more effective due to the attentional engagement music provides.
• The emotional response to music may enhance neuroplasticity via dopaminergic pathways.

For most people, both approaches appear similarly effective. The best choice is whichever one you'll actually listen to consistently.