Assuming this is while tickling is occurring? Well, I guess it'd be the same either way. I don't like loud, shrieking laughter. The type that's as much scream as laugh. In addition to being hard on the ears, it sounds so pained. If I'm tickling someone, its a playful, enjoyable activity we both want. While there is definitely an aspect of control and domination in straddling her waist and running my fingers up and down her sides, I don't consider it to be a sadistic experience.
Its the BD and not SM in BDSM (B also not required. Hell, in a tickle fight there isn't much D either, is there?). I don't consider myself to be enjoying inflicting a negative experience on the lee, and I don't think of the lee as perversely enjoying feeling something negative (like pain). I apologize to the SM fans for not adequately describing their thing, but I feel mine is qualitatively different. The lee wants to be tickled because she enjoys it. It makes her feel good, its affectionate and maybe sexual. She enjoys my ministrations, and I in turn love the impact such a simple thing can have on another.
With all that premise: I prefer a soft giggle or silent laughter. Something giggly and happy sounding. A playful noise that doesn't erupt in screams, but slowly collapses into silent shuddering, a blushing face inaudibly mirthful. A girlish laugh that eggs me on and almost dares me to keep going even if pleading for it to stop. That's the sound I'm looking for.
Yea, I know. TL;DR