My Child Has a Unilateral Hearing Loss
This is a good question. Since I havent personally evaluated your child, I can speak only in generalities.
First, have your sons hearing evaluated every 3-6 months by a pediatric audiologist. His hearing may well remain stable, but the only way that you will know for sure is to have his hearing monitored.
Second, ask if it would be useful to try a hearing aid in the ear that has a hearing loss. You didnt mention the degree of his hearing loss, and a hearing aid might assist him.
Third, if the desired mode of communication for your son is spoken language, then emphasize spoken rather than sign language. To that end, enrich his auditory/language environment. Have a quiet environment. Turn off the TV and music unless that is the focus of the conversation. Narrate all events that are in your sons focus. Speak close to him using full sentences in a clear, melodic voice. His distance hearing and incidental listening will be reduced by his hearing loss, so you need to be more deliberate in your speaking.
And of course, read, read, read aloud! Read at least 10 books per day. Reading aloud is one of the most important things that we can do for any child.
Sing all types of songs, and chant nursery rhymes. Singing engages both sides of the brain, and of course, auditory stimulation is really about brain development. Developing the auditory centers of the brain is the foundation for speaking, reading, and learning.
If your son is not developing the expected spoken language by 18 months, have him evaluated by a speech/language pathologist.
When he goes to school, a sound field system will be necessary in his classroom so that he can clearly hear the teachers spoken instruction.
Best of Luck!