Possible Clues:

• Barman finds how, without Oscar, middleman is unstressed in a manner of speaking
• The "a" sound in "afire"
• Indistinct sound was odd outside church
• Unspecific vowel sound
• Stress-free sound was floating around church
• Kitsch was displaying such a silent vowel
• 'Long Island' sound
• Pronunciation indicator
• Un-stressed vowel
• Sound unstressed, living in Neuschwanstein