A. Exterior noise
B. Interior noise
I had been asked this question in an interview for internship.
The query is from Acoustics topic in chapter Acoustics and Ventilation of Construction & Building Materials
The best explanation: The exterior noise enters the Auditorium either through loose doors and windows on walls and other structural elements having in proper sound insulation. The exterior noise is developed by vehicles, factories, cooling plants, etc. The remedy to correct this defect is to provide suitable sound insulation.