Possible Clues:

• The "e" sound in "they," e.g.
• The "e" sound in "the," e.g
• Either the first or last vowel sound in 'Alaska'
• 'Uh,' phonetically
• Upside-down lowercase "e"
• Agenda's beginning or end
• The "u" sound in "circus"
• Husband and wife beset by endless fraud sound unstressed
• Neutral vowel
• End of an era?