Sound is as effective as smudging or candle spells. Any "happy" sounds will drive off negative energy. I keep a small bell, charcoal and incense, and a small smudge stick in my travel kit ... I rarely need it, but it's handy to have when I do need something to clear out "gunk".
Bottom line? There is no right or wrong way to dispel negative energies so use what you are comfortable with. If you're comfortable experimenting, or one method doesn't work well enough, there's no reason not to use something else.
