Hi and thanks for the query,
the duration of this particular symptom for the past 7 months deserves a keener evaluation. Cold flu
could possibly cause a decrease in the hearing capacity, but this actually rarely goes above 7 months. A critical evaluation of the hearing function with appropriate clinical and paraclinical tests, examination of the ear druma nd canal to see if they are intact could be very helpful. Accumulation of wax alone on the ear drum is capable of reducing the hearing ability.
I strong suggest you book an appointment then with an ENT specialist
to get a clearer and better vision of this problem,
Thanks and best regards,