"soft laugh" is correct and usable in written English.
You can use it when describing someone's laugh, e.g. "Anne let out a soft laugh when she heard her friend's joke."
Outside ' Pretty pretty what a sweet thing you are soft gentle laugh a sexy smile quite angel Does it hide a darker side?
Though it tries mightily to live up to its cute title and premise with soft laughs and sticky predicaments, "Confessions of a Shopaholic" largely registers as a classic story of female self-improvement.
Mr. Richter's "John Kennedy, 1963," in the papier-mâché style of Cologne carnival figures, provides a soft, laughing commentary on the German-American dialogue, culturally ubiquitous in Germany during the second half of the 20th century.
Because while at first it seemed as if Mr. Rock was going to go easy on the room, with soft laughs about the "White People's Choice Awards," you could feel the room begin to cool when he started dropping words like "raping" and "lynching".
The spotted hyena has an extensive vocal range, with sounds ranging from whoops, fast whoops, grunts, groans, lows, giggles, yells, growls, soft grunt-laughs, loud grunt-laughs, whines and soft squeals.
