Ask to have a hearing test either at the Pediatrician's office or at Audiology if you are very concerned. That way you can determine if there is a true hearing loss or not. There are screening tests at the Pediatrician's office to determine if the ear drum moves or not that he/she should be able to do for sure if an official audiology appointment isn't available for another time. At 9 weeks, they may only be able to do the screening test for your infant. I'm not sure. But that's something you can investigate.
Having an infected second ear may be likely especially if not treated with any sort of medication when the first one was looked at. Ear infections can be caused by bacteria that can be treated as well as viruses where antibiotics don't really help. Be sure both ears are looked at and a plan is activated.
We've had our share of ear problems at our household but they've been years in the making. If this is his first ear infection, I don't know if the Pediatrician will refer you out to ENT (Head and Neck Specialists) as it is probably something he/she is capable and willing to treat. Usually ENT referrals are for prolonged ear problems when the Pediatrician can no longer come up with options to treat and the underlying problem may be greater than just a simple ear infection.
I'm sure your Pediatrician will be of help once he/she looks at the overall situation. Best of luck with everything! And I hope the ear infection is resolved soon!