Charged shot audio sequence,How do I get a sequence of sounds to play correctly?

I want to create a sequence of audioclips to be played under certain conditions. Think megaman charge, repeat sound, and then charged shot audio played when button released. Currently when I hold the trigger, the sound repeats over and over playing over itself. I want the charge sound to be played once with the charge repeating sound automatically played after charge is completed until I release the button and then the charged shot sound is played.,I'm creating a charged shot, but can't get the audio to play correctly without overlapping and in the correct order. I'm wanting a charge sound to play when the button is held until the sound ends once, then another sound clip of the end of the charging to repeat until the button is released at which time I will play a charged shot. Think megaman charge then repeat until let go and then shot fire played.