Hearing damage

Exposure to loud noise for long periods of time, such as when you are at work, can lead to a permanent hearing loss.
Excessively loud noise is when you must use a raised voice or shout to carry out a conversation at arm’s length.

The first sign of hearing loss due to noise exposure is difficulty hearing in noisy situations such as at the dinner table, in a crowd, or in any situation where there is competing background noise.

Tinnitus
Sometimes a hearing loss may be accompanied by tinnitus (ringing in the ears or head noises) when there is no external noise present. Tinnitus may come and go, may be aggravated by other loud continuous or impulsive noise, may be triggered by exposure to loud noise, or may be an indication that you have ear damage. It can be a very distressing condition.

Can a hearing aid make up for hearing loss?
Hearing loss is not a simple problem. It cannot be corrected like some vision problems can be with spectacles. A hearing aid is basically an amplifier. It can make up for the loss of loudness, but not for loss of clarity or reduced range of frequencies.

source: Australian Hearing used with kind permission