Using REST, POST implies a create, such as the above 2 actions that create tasks.

So, this could stay a post, b/c maybe you are doing a post to 'create' a listen. Then the action should be called a 'listen' or 'listening' action.

http://stackoverflow.com/questions/1426845/incrementing-resource-counter-in-a-restful-way-put-vs-post

Or, you could do a  PATCH, which would be more appropriate for an update where you are changing a single field.

I probably would leave it a PUT, and give the action a name more consistent with that pattern.