Possible Clues:

• Look briefly into school to give a talk
• It may be announced by tapping a glass
• Maria W. Stewart's 'Why Sit Ye Here and Die?' was one
• Language has its day at school
• How cheeps may be made, in a manner of speaking
• Something given by a valedictorian
• The spoken word
• 'Utterance, talk (6)'
• Formal talk to an audience
• Diction