Object exchange is used to encourage children with no spoken language or limited spoken language to make their wants known.
Items that motivate your child are put in separate clear containers that have lids that your child cannot get off.
To begin teaching your child to make an exchange. Place a lidded clear container with something they are motivated by in front of them. Hopefully they will pick up the container and hand it to you. When you receive the container open it and name the item and give it to your child.
If they do not seem to know what to do with the container you will need a second adult to support you. The second adult will sit behind the child and hand over hand help the child give the container to you. They do not say anything when they do this and neither do you. Over time they will learn what they need to do to get the object they want.
Once your child has had the object for a few minutes put it back in the container and repeat the process. Try to do at least 5 times.
This can be done with toys and also with food. For example, apple in a lidded clear container. Your child gives you the container and you say apple and give them a piece of apple to eat. Once the apple is eaten repeat the process so they have to request if they want more.
Once they are confident to make this exchange. Move further away from them so they have to bring the container to you. You may need an adult to support you with this if your child is unsure what to do because you are further away. The idea behind this is that they will learn to come and find you if they want something in one of the clear lidded containers.
There is a nice video clip demonstrating object exchange at https//vimeo.com/417231581/34cca313a7