A server room contains 120 identical high-performance cooling fans. When all fans are operating at full capacity, the sound-intensity level at the central monitoring console is 98 dB98\text{ dB}98 dB.
Estimate the sound-intensity level at the central monitoring console when 105 of the fans are switched off for scheduled maintenance.
You should assume that:
Describe two changes to a person's hearing that may result from prolonged exposure to sound at 98 dB98\text{ dB}98 dB without hearing protection.