Yes, that is basically how it works. But there is a lot of work for them to begin to understand words. The word must be repeated until the brain associates that particular signal to the word. The original model of the cochlear implants were called single channel because a single wire was inserted into the cochlea. Some people were able to learn to hear, and speak with those, but that was not the original intention of device. It was sold to allow the deaf to identify enviromental sounds like a car honking. The later versions of the implant like the Nucleus 22 had many more electrodes inserted into the cochlea, and thus stimulated a greater number of sites along it and helped the deaf get a greater range of stimuli. Many that could hear before they went deaf were able to very quickly become close to hearing again.

I know quite a bit about the implants because my youngest son was deaf from meningitis at four months old. He was the youngest implant recipient at the time at 2 years old. He could hear the environmental sounds the minute they hooked him up the first time. The doctors and audiologists were amazed at his first reaction. They had not expected it to be that drastic. His first was a single channel, and with a lot of spreech therapy he learned to speak with that unit. He received a multi-channel a few years later.