A comparison has been made of air conduction threshold changes up to 1 year after myringotomy, aspiration of middle ear fluid, and insertion of ventilation tubes in ten patients with bilateral and 12 with unilateral secretory otitis media (SOM). Pure tone air conduction thresholds have been analyzed in three frequency groups: Low frequency (LF; 0.25, 0.5, and 1 kHz), high frequency (HF; 2,4, and 8 kHz), and extra-high frequency (EHF; 10, 12, 14, and 16 kHz). In the LF and HF ranges, significant improvement came during the first 24 hours after intubation, while in the EHF range, threshold lowering occurred gradually over the following 2 months. Possible explanations for these findings are discussed.
