Spectrotemporal Assessment of Pulse-synchronous Sound in the Outer Ear Canal in Patients With Pulsatile Tinnitus

OBJECTIVE: To describe and investigate the diagnostic value of a spectrotemporal assessment of sound recorded from the outer ear canal in patients with pulsatile tinnitus. STUDY DESIGN: A small microphone was placed in the outer ear to record sound. Meanwhile, a pulsoximeter recorded heartbeats. Both signals were visually assessed for pulse-synchronicity. SETTING: Tertiary referral center. PATIENTS: One hundred fifteen patients presenting with pulsatile tinnitus (PT) who had a normally aerated middle ear and in whom a radiologic explanation was identified or excluded with CT-angiography (CTA) and/or neuroangiography (NA). INTERVENTION: Diagnostic. MAIN OUTCOME MEASURE: The diagnostic value of our method, including sensitivity and specificity. RESULTS: Sixty-nine (60%) of all patients had an extra pulse-synchronous sound in the spectrogram at one or both ears that was clearly visible in 60 and somewhat more difficult to recognize in 9 patients. In 86 (75%) of all patients, we found a vascular cause of PT. Two patients with a pulse-synchronous sound at one or both ears had no vascular explanation on both CTA and NA (false-positive). In 19 patients, we did not see a pulse-synchronous spectrogram in either ear, although radiologic workup showed a vascular cause (false-negative). Five of them had an arterial cause of PT, in 14, a venous cause was found. CONCLUSIONS: Transcanal sound recording in patients presenting with PT provides diagnostic information on the likelihood of a vascular origin, although sensitivity is limited. This noninvasive method can help the clinician to decide on the appropriate diagnostic workup, avoiding unnecessary burden, risk, and costs of diagnostic imaging, including NA.