Gasp: a sudden, sharp intake of breath, often due to shock, surprise, or difficulty breathing.
• Catch one's breath: to take a sudden, sharp breath, often due to surprise or exertion.
• Gulp: can imply a sudden intake of breath, often accompanied by a swallowing motion.
• Hiss: not typically a breath sound, but can be a sharp exhalation.
• Snort: a sudden, explosive exhalation through the nose.