Possible Clues:

• Part of a public address system
• One may be put in the corner of a classroom
• What could broadcast duo with sparkle and energy?
• Part of a sound system
• Sound projector
• Part of hi-fi system
• Sound equipment, say, with more garish cover
• Part of stage equipment OK as prelude plays
• Amplifying equipment such a person doesn't need?
• Electronic megaphone