Not just sonic booms though. Those engines were spectacularly loud going over populated areas. It used to come over me in the western edges of London on a regular basis, and the whole earth shook when it did.
I remember spending a lot of time at Heathrow in the BA departure lounge waiting for flights to Edinburgh - normally you couldn't hear very much (if anything) from outside. Then the whole place would shake and you'd hear an impressive roar from outside and you'd know a Concorde had taken off.
Concorde was only louder than the rest on takeoff and initial climb out - because the reheat was on. Reheat is stupidly loud. Reheat was needed as it was optimised for super cruise (sustained supersonic) - something even fighters aren't, which made it very inefficient at takeoff speeds.
On approach and cruise it wasn't that much different from other jets of the era.
Modern engines could be far quieter and not need reheat for takeoff.
Several years ago a Eurofighter was scrambed to intercept what they thought was a hijacked plane; I didn't realise this at the time but the sonic boom shook my flat and the windows, not that I minded in that case, but I wouldn't want to make a habit of it.
Which set me to thinking, how much energy must be sapped away by the sonic bow shock, to make such a loud sound across such a wide area must be be exteremly inefficient.
Also I've been interested in Max-Q, the fact that a rocket has to limit its speed to reduce aerodynamic stresses on its structure, not something I've thought much about before.
A "regular jet" has turbofan engines where the center section of the jet, the part that actually compresses air and burns fuel, is used to spin a big fan which supplies a good chunk of the thrust. The fan is relatively quiet compared to the actual fuel burning section of engine because it is exhausting gas at much lower pressure, think popping a balloon vs popping a tire. For a variety of reasons that you can google high bypass turbofan engines are not used on supersonic aircraft. This means all that thrust is coming from the actual engine itself.
Per unit of thrust an aircraft that doesn't use turbofans is just going to be louder.
So Concorde is just going to be louder than a "regular jet" but nothing special compared to any other jet making the same amount of thrust from similar engines. For acoustic purposes you can think of the Concorde as basically being two heavy fighter aircraft.
Edit: Running the numbers based on Wikipedia specs for thrust with afterburners the Concorde is making about the same amount of thrust as four F18s. So throttle on the firewall Concorde should make about as much noise as the Blue Angels. That said, lighting the burners over a populated area would be a great way to wind up looking for a new job.
Yes, a lot louder. I lived well outside London, and I'd say Concorde flying over Reading (by which point it was _high_) was louder than the memorable time a C-5 decided to take off from Greenham Common right over my house.
I used to live near central London (NW6) and would be driven mad by Heathrow aircraft, because many late-night Asia-bound departures would overfly my house. It often seemed roof-shakingly loud, and was incredibly annoying when I was trying to get to sleep. (Although there was supposed to be an 11PM curfew, they would often depart late, sometimes after midnight.)
Right now I live in far west London (UB3), only a mile or so from Heathrow's northern runway. On the 6th floor. It's blissfully quiet. I can see the aircraft but not hear them. Turns out that aircraft coming in to land, even relatively close at low altitudes, are much less noisy than departing aircraft directly overhead.
I slowly learned to hate the Blue Angels because the city of Seattle let them buzz downtown during their practice sessions every year, with after burners. If the burners went on anywhere over downtown you had to pause your conversation. Indoors.
Every fucking year. Including the years after 9/11, when the sounds of a military jet in a densely populated area took on more sinister undertones. Oh shit, are we fucked? No, it,'s just SeaFair.
First year: Oh cool, Blue Angels! After five years? Fuck you, Blue Angels.
Do you mind me asking which city that is? I'm curious because after living in multiple big cities I found that sometimes one city was much louder than living next to the huge airport of another city.
This being said regular passenger planes are not that noisy compared to military and supersonic ones.
I live in London and in my experience, the vast majority of problematic urban noise comes from two sources: overflying aircraft (mostly from to LHR and LCY airports), and modified or poorly maintained motorcycles.
Aircraft are improving with each generation but are still extremely noisy when they're directly overflying you, even many miles from the airport.
While there are certainly other sources of urban noise, like heavy goods vehicles and construction, these are strictly regulated and enforced with regards to operating times, etc in the UK - while noise from aircraft and private vehicles is not.
Sirens (fire, ambulance, police) can also be very loud, but I'll give them a pass because they are actually serving a useful purpose and saving lives. In the future when vehicles are quieter due to electrification, I think we'll be able to reduce the volume of emergency sirens too.
Those weird scallops on the back of all recent vintage Boeing planes are for noise reduction.
I couldn't find a quote or number on how many decibels it reduces the engines, except a note that:
| The acoustic liners and chevrons are such effective noise suppressors that several hundred pounds of sound insulation may be eliminated from the fuselage.
I'm just guessing but Shenzhen might be an outlier when it comes to "regular" noise pollution in a city. Most cities would be comparatively quiet and hypersonic flights over them would be quite disturbing.
