Using cotton in your ears does not work. Have your hearing tested by an audiologist. Be aware of noise in your environment and control what you can. To control noise on the farm, you should maintain exhaust systems, using good quality mufflers on every machine. Properly maintained and lubricated machinery helps to reduce noise.
Tractor cabs in good condition reduce noise levels.
When buying equipment compare noise level ratings. An evaluation by an audiologist is recommended. When a medical problem is suspected to be the cause of hearing loss, a physician should be seen. But hearing loss may be permanent in the affected ear. Ear protection to prevent the hearing loss from worsening is important.