We don't have synonyms for breathiness yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are breathless, breathings and breathiest.
"{{quote-news|pagetitle=breathiness|year=2007|date=February 15|author=Anne Midgette|title=A New Work for Cello, Played Upon a Veteran|work=New York Times|url=http://www.nytimes.com/2007/02/15/arts/music/15glas.html"
°The result or product of being breathy.
"{{quote-news|pagetitle=breathiness|year=2008|date=May 9|author=Allan Kozinn|title=From Energetic Players, a Mix of Modernism|work=New York Times|url=http://www.nytimes.com/2008/05/09/arts/music/09arge.html"
"{{quote-news|pagetitle=breathiness|year=2007|date=February 15|author=Anne Midgette|title=A New Work for Cello, Played Upon a Veteran|work=New York Times|url=http://www.nytimes.com/2007/02/15/arts/music/15glas.html"
°The result or product of being breathy.
"{{quote-news|pagetitle=breathiness|year=2008|date=May 9|author=Allan Kozinn|title=From Energetic Players, a Mix of Modernism|work=New York Times|url=http://www.nytimes.com/2008/05/09/arts/music/09arge.html"