Possible Clues:

• Kitchen-to-bedroom sound system
• Way to communicate in period without company
• Popular expression around firm for a means of contacting others
• Phone system Bury firm marketed at first
• Stylish Hilary for one maintains business link?
• Office squawker
• Organised crime not building telephone system
• Talking bird flying back and forth between stone boxes
• College in Orient sabotaged mass communications system
• Switch on metric paging system