A holder for a telecommunications device includes a container including a side wall connected to a base. Together the side wall and base define a cavity. Side wall defines an opening of the container at an end of the side wall distal to the base. A resilient insert is disposed inside the cavity. The insert includes a bottom portion that abuts the base and a feature for releasably retaining the device inside the container. A lid is in selective locking engagement with the side wall's distal end. When in locking engagement, the lid encloses the opening of the container to retain the device inside the holder, and to muffle a sound and/or a vibration produced by the device. A locking mechanism is operatively attached to the container and/or the lid, and holds the lid and the container together when the lid is in locking engagement with the distal end.