Another type of synchronization primitive specifies that an event is to be repeated until certain other events occur. Thus, we can specify that a certain sound-space event is to be repeated for the duration of the rendering of an object. Here, the duration of the event is specified in terms of other events taking place in the audio formatter. We can picture this as turning on a conceptual switch on the audio player and turning it off at a later time. This is achieved by executing a loop-forever statement, as discussed in s:com_spaces_synch; such an event is terminated when the block in which it appears is ready to terminate.