HIS Tinnitus Assessment & Management 2 — Questions and Answers
Question 1: What is minimum masking level (MML) in tinnitus assessment?
- The loudest sound at which a patient is comfortable
- The lowest level of broadband noise required to just mask the patient's tinnitus, measured in dB SL above the patient's hearing threshold (Correct answer)
- The level at which tinnitus becomes permanent
- The minimum gain required in a hearing aid for the patient to hear speech
Correct answer: The lowest level of broadband noise required to just mask the patient's tinnitus, measured in dB SL above the patient's hearing threshold
Minimum masking level (MML) is determined by increasing broadband noise until the patient reports their tinnitus is just covered, expressed as dB SL above the hearing threshold—it quantifies tinnitus loudness and guides sound therapy levels.
MML is measured using a broadband noise presented ipsilateral to the tinnitus ear, starting below threshold and increasing until the patient reports the tinnitus is just masked. It is expressed in dB SL (sensation level, above threshold). MML is typically only a few dB SL (often 5-15 dB SL), reflecting the fact that tinnitus is a relatively faint signal whose annoyance comes not from loudness but from its inescapability. MML helps set sound therapy levels in TRT (sounds should be set below MML to provide mixing rather than masking).
Question 2: What is residual inhibition in tinnitus and why is it clinically relevant?
- A permanent cure for tinnitus following sound exposure
- A temporary reduction or complete suppression of tinnitus following the cessation of a masking sound, lasting seconds to minutes (Correct answer)
- The inhibition of hearing aid gain in the presence of tinnitus
- The patient's ability to ignore tinnitus over time
Correct answer: A temporary reduction or complete suppression of tinnitus following the cessation of a masking sound, lasting seconds to minutes
Residual inhibition (RI) is the temporary reduction or disappearance of tinnitus after a masking stimulus is turned off—it demonstrates that tinnitus can be temporarily suppressed, which is encouraging for patients and informs the neurophysiological understanding of tinnitus.
Residual inhibition is tested by presenting a broadband masking noise at 10 dB above MML for 60 seconds, then abruptly turning it off. The patient reports the duration and degree of tinnitus suppression that follows. RI can last from seconds to minutes. Its presence demonstrates that auditory neurons generating tinnitus can be temporarily inhibited by sound. This finding is encouraging for patients who may despair that tinnitus is unchangeable, and may help predict response to certain sound therapies.
Question 3: Cognitive Behavioral Therapy (CBT) is considered a first-line treatment for which tinnitus presentations?
- Mild tinnitus with no emotional distress
- Tinnitus associated with significant psychological distress, anxiety, insomnia, or depression—CBT is the most evidence-based treatment for tinnitus-related psychological disability (Correct answer)
- Pulsatile tinnitus of vascular origin
- Tinnitus in children under age 10
Correct answer: Tinnitus associated with significant psychological distress, anxiety, insomnia, or depression—CBT is the most evidence-based treatment for tinnitus-related psychological disability
CBT has the strongest evidence base for reducing tinnitus-related psychological distress, depression, anxiety, and sleep disturbance, even though it does not reduce the tinnitus sound itself; it changes the patient's emotional and cognitive response to tinnitus.
Multiple systematic reviews and Cochrane reviews support CBT as the most effective evidence-based intervention for tinnitus-related disability. CBT does not reduce the perceived loudness of tinnitus but significantly reduces its emotional impact by: modifying catastrophic thoughts (cognitive restructuring), reducing tinnitus-focused attention and safety behaviors, improving sleep (CBT for insomnia is highly effective in tinnitus patients), and reducing comorbid anxiety and depression. CBT can be delivered in-person, in groups, or via internet-based platforms.
Question 4: What is the relationship between stress and tinnitus severity?
- Stress has no effect on tinnitus
- Stress activates the limbic and autonomic nervous systems, which amplify the emotional impact of tinnitus and may increase perceived tinnitus loudness and annoyance through descending auditory pathway modulation (Correct answer)
- Stress always causes new tinnitus
- Tinnitus only worsens with physical stress, not psychological stress
Correct answer: Stress activates the limbic and autonomic nervous systems, which amplify the emotional impact of tinnitus and may increase perceived tinnitus loudness and annoyance through descending auditory pathway modulation
Psychological and physiological stress activates the limbic system and autonomic nervous system, which have bidirectional connections with the auditory system; this can amplify the perceived annoyance and loudness of tinnitus and create a reinforcing distress cycle.
The neurophysiological model of tinnitus (Jastreboff) emphasizes that tinnitus distress arises primarily from limbic and autonomic nervous system activation triggered by the tinnitus signal. Stress, anxiety, and depression activate these systems, increasing their sensitivity and creating a feedback loop: tinnitus leads to stress, which leads to a heightened limbic response, which leads to more bothersome tinnitus, which leads to more stress. Stress management strategies (relaxation, mindfulness, CBT) are therefore integral to tinnitus management.
Question 5: What audiological finding most commonly predicts poor benefit from hearing aids for tinnitus?
- Bilateral sensorineural hearing loss
- Normal audiogram (tinnitus without significant hearing loss), where hearing aids provide no amplification benefit and therefore limited masking effect (Correct answer)
- Severe hearing loss requiring high-power hearing aids
- High-frequency hearing loss above 4000 Hz only
Correct answer: Normal audiogram (tinnitus without significant hearing loss), where hearing aids provide no amplification benefit and therefore limited masking effect
Patients with tinnitus but normal or near-normal audiograms cannot benefit from amplification-based tinnitus relief, since hearing aids are not indicated for normal hearing and provide minimal acoustic masking benefit without amplifying environmental sound.
Hearing aids are most effective for tinnitus relief when the patient has a concurrent hearing loss, because amplification restores ambient sound audibility and reduces the quiet environment where tinnitus is most noticeable. For patients with normal audiograms, hearing aids are not clinically indicated. These patients are better served by dedicated sound generators, tinnitus-specific sound therapy apps, TRT counseling, CBT, or investigation of other etiologies.
Question 6: What is notched music therapy (NMT) for tinnitus and on what principle is it based?
- Music played very loudly to mask tinnitus permanently
- Music processed to remove frequencies around the patient's tinnitus pitch, hypothesized to reduce neural activity at that frequency through lateral inhibition in the auditory cortex (Correct answer)
- A form of music therapy involving active singing to distract from tinnitus
- Music combined with electrical stimulation of the auditory nerve
Correct answer: Music processed to remove frequencies around the patient's tinnitus pitch, hypothesized to reduce neural activity at that frequency through lateral inhibition in the auditory cortex
Notched music therapy removes a frequency band centered on the patient's tinnitus pitch from music, which is hypothesized to reduce cortical tonotopic map reorganization and decrease neural hyperactivity at the tinnitus frequency via lateral inhibition.
Notched music therapy (also called Tailor-Made Notched Music Training) was introduced by Okamoto et al. (2010). By removing a frequency notch centered on the tinnitus pitch from music, the auditory cortex neurons representing adjacent frequencies (active during music listening) suppress activity at the tinnitus frequency through lateral inhibition. Over weeks to months of daily listening, this may reduce the cortical hyperactivity maintaining the tinnitus percept. Several controlled studies have shown modest but significant reductions in tinnitus loudness and THI scores.
HIS Tinnitus Assessment & Management 2
What is minimum masking level (MML) in tinnitus assessment?