Employers try to put their employees in a set routine without the employees realizing it. This routine restricts the employees and doesn't allow them to express their feelings or thoughts. Consent is the convert control without objection. This is where the employees know about the routine and realize they are working in an environment that restricts them but does it willingly or at least for understandable reasons. One reason may be that they have bills that have to be paid and this is the highest paying job that they have found.
Involvement is the free expression of ideas.
These ideas come from the corporation and its managers. The employees are involved only because they want to make sure their grievances are heard and managers see this as a chance for the employees to blow off some steam. This is far from having a voice in the company. Their voice is heard when the employees go from involvement to participation. Participation is when the employees have a chance to speak their minds and ideas.