I am Dr Ravinder Sharma.
On the basis of information provided it appears that your brother has a traumatic perforation of the drum. I am concerned about the inner ear
and the ossicles
too (as the length of external auditory canal is only 24 mm or 2.4 cm )
I advise you for a ENT consultation and some tests like examination under microscope and audiometry
to resolve the issue
I hope this answers your concerns. Feel free to contact me if you want further information about it