Evaluation of Pure Tone Audiometry in Paediatric Patients with Otitis Media with Effusion: A Retrospective Study

Otitis media with effusion (OME) frequently impairs sound transmission in children, yet the severity and shape of the resulting hearing loss are not uniform. How effusion volume and viscosity contribute to this variation remains insufficiently defined. To investigate how middle-ear effusion characteristics relate to frequency-specific air-conduction thresholds in children with OME. Records of 180 children aged 3–12 years with persistent OME who underwent myringotomy, with or without ventilation tube insertion, were reviewed retrospectively. Air-conduction thresholds at 250, 500, 1000, and 2000 Hz were available for 360 ears. Operative descriptions classified effusion volume as partial, half, or full and viscosity as serous, mucoid, or purulent. Generalised estimating equation (GEE) models accounted for correlation between ears within the same child and included age, sex, OME duration, and ear side as covariates. The mean four-frequency hearing threshold increased from 20.02 ± 3.12 dB HL in ears with partial effusion to 23.38 ± 8.14 dB HL with half effusion and 48.61 ± 3.85 dB HL with full effusion. After adjustment, full effusion was associated with a 28.21-dB higher threshold than partial effusion (95% CI, 27.20–29.22; P < 0.001). Serous effusion showed predominantly low-frequency threshold elevation at 250–500 Hz, whereas mucoid effusion was associated with a nearly flat audiometric profile across 250–2000 Hz, with mean thresholds of approximately 48–49 dB HL. Purulent effusion showed its highest mean threshold at 2000 Hz (51.25 ± 3.54 dB HL), although this finding was based on only eight ears. Frequency-specific hearing profiles differed significantly across effusion viscosity groups (interaction P < 0.001), with a significant frequency-by-volume interaction also observed (P < 0.001). Age, sex, and OME duration were not independently associated with hearing threshold after adjustment for effusion characteristics. The auditory effect of childhood OME was not uniform across effusion characteristics. Increasing effusion volume was associated with poorer hearing thresholds, while serous and mucoid effusions showed different frequency-specific profiles. These results support detailed audiological assessment in persistent OME while recognising that the observed audiometric patterns cannot be attributed to viscosity independently of effusion volume.