There are several solutions.
Either allocate a specific channel for sounds that are meant to block each other and play all of them on that channel. Alternatively, use your own channel allocation so you know what channel to stop. Alternatively use "stop sample". Or you can use
my sound system which lets you treat sounds as objects. With the last solution, set the emitter's "Continuous Mode" to 1 (required to control the sound while it's playing) and set "Stop Sound" to 1 when you wish to stop the playback (which also removes the emitter).