As a lay term rather than a linguistic description (Vote #1 Clarissa Lohr: Clarissa Lohr’s answer to What is proper name of the sound when pushing air through nose?), I was racking my brains: I was sure English had a word, and couldn’t place it. Something to do with flared nostrils. And huffiness.
Our fellow question-answerers at Stack Exchange are a step ahead of me:
Is there a term for letting out an exasperated sigh through the nose?
a snort articulated as a syllabic m or n with a voiceless onset and ending in a nasal h or a glottal stop; often read as ˈhəm(p)f.
That’s a voiced sound, and is in fact what I’ve only ever seen spelled as mpf; humph is 17th–19th century. From Stack Exchange, it looks like it’s the closest English has; someone explicitly asked for the voiceless equivalent of humph there.
PS: The reason I’m here and not on Stack Exchange:
Welcome to EL&U. Please note that this is not a discussion forum, but a Q&A site which seeks to provide definitive answers. As such, your answer would be greatly strengthened with an explanation— why would you propose suspirates? What is its dictionary definition? What are some examples in literature or journalism? I strongly encourage you to take the site tour and review the help center for additional guidance. – choster Oct 20 ’16 at 3:10
Makes for better answers. Makes for much worse socialising…