The A319/A320, like most aircraft, have some unique noises due to different system designs. Many of the noises will be entirely dependent on where on is seated in the cabin.

Some of more pronounced sounds on the A319/A320:
- Engine "buzzsaw" sound on takeoff, particulary noticable in the front of the aircraf. This is the sound coming from the fan blades as the end of the blades actually go at super-sonic speed at full power.
- Hydraulic system pumps / system loading/unloading, heard on the ground typically pre or post flight. Make a cyclical up and down sound, often like a barking dog. Most noticable over the wing.
- Brake release, heard while taxing, most heard over the wing, when the brakes are released, like a small thud.

Other aircraft have certain "unique" sounds, some that come to mind:
757: engine "growl" at takeoff, the whine of the flap motors
DC-9: the old-school whine of the JTD8 engines, the "thud" of flap deployment, the low-whine of the hydraulic system on the ground at the gate
Saab: turboprop - the condition changes of the prop
CRJ: the loud thud of the landing gear deployment