3Pitch, Loudness and Sound Quality

FPerceived pitch and the edge of hearing loss

Most subjective tinnitus has a recognisable pitch, and that pitch is not random. High-pitched tinnitus — ringing, whistling, hissing — is the commonest variety and typically accompanies high-frequency sensorineural hearing loss from noise exposure or presbycusis. Low-pitched tinnitus — buzzing, roaring, humming — is more often linked to low-frequency or Menieric processes. [2013]

A robust observation is that the perceived pitch tends to fall near the edge frequency of the hearing loss — the region where the audiogram drops away. This fits the deafferentation account: where the cochlea stops feeding the brain normal input, central neurons reorganise and over-fire, and the resulting phantom tone reports from that border zone. [2014]

TPitch matching: what it can and cannot do

Pitch can be quantified by pitch matching, in which the patient adjusts a tone until it resembles their tinnitus. It usefully confirms the high-frequency, edge-of-loss pattern, but it is notoriously slippery: patients confuse the octave of the match (the octave confusion problem), and repeat measurements drift. [2013]

For these reasons pitch matching is more a research and characterisation tool than a treatment-defining measurement. It can inform notched-sound or frequency-targeted therapies and document the percept, but a clinician should not over-interpret a single match. The qualitative descriptor the patient offers — tonal, noise-like, or mixed — often carries as much clinical meaning as the matched frequency.

TMeasured loudness is faint

Here lies one of the great surprises of tinnitus psychoacoustics. When loudness is measured by loudness matching against an external tone, the result is usually only a few decibels above the patient’s own threshold — commonly in the range of roughly 5–15 dB sensation level. [2013] In absolute terms the phantom sound is faint.

A related measure, the minimum masking level (the lowest external sound that just covers the tinnitus), is also typically low. The mismatch between how loud the tinnitus feels to a distressed patient and how faint it measures is itself a teaching point: the brain’s attentional amplification, not raw signal strength, is doing the work.

CSound-quality descriptors

Beyond pitch and loudness, the quality of the sound carries diagnostic weight. A pure tonal percept favours a cochlear/deafferentation origin; a noise-like hiss or roar may accompany broad cochlear damage or low-frequency disease; a clicking or fluttering quality points away from sensorineural tinnitus toward middle-ear or palatal myoclonus. [2013]

Patients commonly report a mixture — a dominant tone over a background hiss, sometimes several tones. Capturing this in plain descriptors (and, where available, with sound-demonstration libraries) helps validate the patient’s experience and refines the differential. Quality, pitch and loudness together form the psychoacoustic fingerprint of the percept. [2013]

CThe loudness–distress disconnect, revisited

The clinical payoff of all this measurement is paradoxical: the psychoacoustic numbers predict suffering poorly. Matched loudness, minimum masking level, and pitch correlate weakly with handicap; distress is driven instead by the emotional and attentional response. [2013] A patient with a 6 dB SL match may be incapacitated while another with a louder match copes.

This is why severity grading relies on impact questionnaires rather than psychoacoustic matches, and why counselling that targets the reaction outperforms efforts aimed only at the signal. Pitch, loudness and quality remain worth characterising — for diagnosis, for therapy targeting, and for validating the patient — but they are not a severity scale. [2014]