If you have to use an aquarium air pump, I can recommend the Tetra Whisper series as they are a good design that is quiet and is not expensive.
Tetra Whisper Aquarium Air Pump Minimal Noise Maximum Air Flow 10
Tetra Whisper Aquarium Air Pump for Fish Tanks 20 to 40 Gallons
The Best Aquarium Air Pump Tetra Whisper 100
Tetra Whisper Air Pump Review
Air Pump for Aquariums Whisper Easy to Use Non-UL up to 10 Gals
Tetra 77851 Whisper Air Pump : : Pet Supplies
The Best Aquarium Air Pump Tetra Whisper 100
Tetra Whisper Easy to Use Air Pump for Aquariums (Non-UL)
A review of the Tetra Whisper Air Pump
Air Pump Testing Begins - Aquarium Co-Op vs Tetra Whisper
Tetra 26075 Whisper Aquarium Air Pump AP150, up to 150-Gallon
Tetra 77848 Whisper Air Pump 20 to 40 Gallons, for Aquariums
Tetra Whisper Easy to Use Air Pump for Aquariums (Non-UL) up to 10
Tetra 26075 Whisper Aquarium Air Pump AP150, up to 150-Gallon