Hearing loss is an impairment of the hearing function while deafness is a profound hearing loss.
Hearing loss can be caused by a mechanical problem in the ear canal or middle ear that obstructs the sound conduction (conductive hearing loss) or by injury to the inner ear, the auditory nerve or auditory nerve pathways in the brain (sensorineural loss of hearing). The two types of hearing loss can be distinguished by comparing how a person hears the sounds conducted by air and listen as conducted by the bones.
Hearing tests with a tuning fork can be done by a specialized doctor, but the best way to test the hearing is in a soundproof chamber and with an audiometer (specialist in hearing loss), using an electronic device that produces tones and sounds in specific volumes. The conduction of sound by air in adults is measured by placing a vibrating tuning fork that is close to the ear, in order to make the sound travel through the air into the ear. A hearing loss or a subnormal hearing threshold (the smallest sound that can be heard) may indicate the presence of a problem in any part of the hearing (the ear canal, middle ear, inner ear, the auditory nerve or channels of the auditory nerve in the brain).
Try this free online hearing test to get an idea of your actual level of hearing accuracy. This is not just a frequency hearing test but a much more advanced technique providing accurate results.