PURPOSEThis study aims to evaluate the validity and reliability of tubomanometry (TMM) in diagnosing obstructive Eustachian tube dysfunction (OETD) before balloon Eustachian tuboplasty (BET).METHODSA prospective cohort study was conducted, involving 25 patients with sinonasal pathology, 75 patients with middle ear disease, and 25 healthy subjects, totaling 250 ears. All participants underwent comprehensive physical examinations, including TMM, nasal videoendoscopy, otoendoscopy, Valsalva maneuver (VM), tympanometry, and audiometry. Additionally, various scales such as ETDQ-7 and ETS-7 were employed. Tympanometry served as the gold standard for assessing OETD, and comparisons were made among the measures across the three groups.RESULTSAmong the 125 participants, 44.8% (n = 56) were female, and 55.2% (n = 69) were male, with ages ranging from 19 to 93 years (M = 48.5; SD = 15.6). In our study, VM demonstrated high sensitivity (86.3%) when tympanometry was considered the gold standard. Conversely, TMM, ETDQ-7, and ETS-7 exhibited high specificity, with ETDQ-7 showing the highest specificity (87.4%). Regarding TMM, all R values in patients within the middle ear disease group were pathological (R > 1).CONCLUSIONTMM has exhibited notable specificity as a diagnostic tool compared to tympanogram and VM. Nonetheless, the combination of TMM and ETDQ-7 has enabled us to conduct a diagnostic assessment with high sensitivity and specificity for chronic OETD diagnosis.