A 30 yrs old female present with hearing loss and following audiogram is obtained. What is her most likely diagnosis?

Wide AB gap (conductive hearing loss) on left side with carha's Notch (dip at 2000Hz) in Bone conduction indicates Otosclerosis PTA in Otosclerosis:1. Air conduction is poor & worse for lower frequencies. * 2. Large AB gap *3. Bone conduction is normal. *4. In some cases, there is a dip in bone conduction curve. *5. It is different at different frequencies but maximum at 2000 Hz and is called Carha's notch. Boiler's notch is a similar dip in BC and AC curve but at 4000 Hz seen in noise induced hearing loss.