the sound may be most probably due to poor ventilation of middle ear .
This occurs as the eustachain tube present behind the nose and connected to the middle part of ear gets closed and not able to open when there is pressure difference .
I hope you do not have allergic nose or with nasal obstruction
. , if it is so then you need to treat it first as recurrent infections will not allow the tube to work.
You must go for walk daily in the morning so that natural decongestant adrenaline
will be secreted in the body and which will keep the tube open.
take care of reflux , ie acidity.
Take care of these things and report back after 10 days.