I can guarantee that every measure that has been put in place to protect interpreters' hearing health and safety apply to both employees and freelance interpreters. It applies to everyone. Whether or not it is in the contract, the measures are here to stay. All interpreters benefit from the technological innovations arising from the studies we do.
Yes, the reference to them is brief, but we did not feel a need to describe them, since they are included in the commitments we have made and we will never be going back on those measures, for anyone.