How long will i not be able to hear out of my left ear with an ear infection?

10-21 days: Maybe sooner depending on how inflammed and how much fluid there is behind the eardrum.

Hearing & Ear Infect: Fluid may persists for weeks after an ear infection -- 60% clear by 4 weeks, 75% clear by 8 weeks, and 95% clear by 12 weeks after infection. Gently, trying blowing your nose, hoping to clear your ears. Taking an oral decongestant may help, but "clearing" the ears with valsalva (popping the ears) maneuvers works best. It should not hurt, and may not clear with each attempt. Keep trying.

Usually < 3 months: When you get fluid behind your ear drum from an ear infection, or sometimes from just a cold, 50% of people will have the fluid clear up in one month, 70% by 2 months, and 90% by 3 months. If it is still there after that, you should see an ENT who might recommend putting a tube in to drain the fluid and may also put a scope through your nose there is not a blockage of the drainage from the ear.