Possible Clues:

• Orchestra’s final sound?
• Sound unstressed after chief visiting was abused
• The 'u' sound in 'census'
• Common sound coming from some Bosch washers
• Sound that starts "around"
• Sound that starts 'around'
• Phonetician's ''uh''
• Middle syllable of “syllable,” e.g
• Right-of-centre putsch against Washington — sound of America's extremists?
• Dumb sound?