Abstract: A cup is readily converted to an acoustic megaphone by removal of the base. The paper construction, enabled by the features of the invention, offers a good printing surface and simultaneously ensures that the cup is biodegradable. In a first embodiment, a removable tape seal is used to releasably seal and retain a cup bottom to cup side walls. In a second embodiment, a more permanent seal is provided, along with a tear cord. Other embodiments illustrate pull tabs, handles, and a releasable adhesive. The base may also only be partially separated, thereby opening the cup into a horn, while still retaining the base to reduce the amount of waste paper which may become scattered.