Engine sound behavior in higher altitudes

[Spiderschwein 0]

Hello,

Everytime I fly in real life and get a seat forward of the engines, I experience that the engine noise gets quieter with increasing altitude.

In takeoff and initial climb phases it is pretty loud, but in higher altitude climb it becomes more and more silent and in cruise when the RPM decreases it is nearly unnoticable.

I noticed this effect also in many cockpit videos, theres only wind noise audible in CRZ flight.

Maybe it would be possible to model this effect also on the upcoming PMDG products?

The 737NGX and 777 have a really great sound package that makes you think flying the real one if you close the eyes, modeling this noise decrease effect would make the sound experience absolutely perfect in my opinion.

At the moment I turn the engine noise so low that it is overtoned by the wind and other cockpit noises, but that turns down the realism level on the ground and initial climb phases because it is too silent for this phases of the flight.

[AAfan 49]

Hello,

Everytime I fly in real life and get a seat forward of the engines, I experience that the engine noise gets quieter with increasing altitude.

In takeoff and initial climb phases it is pretty loud, but in higher altitude climb it becomes more and more silent and in cruise when the RPM decreases it is nearly unnoticable.

I noticed this effect also in many cockpit videos, theres only wind noise audible in CRZ flight.

Maybe it would be possible to model this effect also on the upcoming PMDG products?

The 737NGX and 777 have a really great sound package that makes you think flying the real one if you close the eyes, modeling this noise decrease effect would make the sound experience absolutely perfect in my opinion.

At the moment I turn the engine noise so low that it is overtoned by the wind and other cockpit noises, but that turns down the realism level on the ground and initial climb phases because it is too silent for this phases of the flight.

I believe this isnt done because it is a limitation of the simulator.

[Tabs 2,790]

There's no variable control of this in FSX based on speed or altitude - the engine sound either plays or it doesn't. The effect in real life happens because the air is so thin at cruise. (sound is a vibrational propagation through a "fluid" be that air, water etc) If it bothers you that much, just go into the FSX sound settings at a certain altitude and turn the engine slider down.

[Spiderschwein 0]

[ajpongress 467]

There's no variable control of this in FSX based on speed or altitude - the engine sound either plays or it doesn't. The effect in real life happens because the air is so thin at cruise. (sound is a vibrational propagation through a "fluid" be that air, water etc) If it bothers you that much, just go into the FSX sound settings at a certain altitude and turn the engine slider down.

 

Could variations of the current engine sound files at different volumes be triggered when the plane reaches a certain altitude?

I.E. @ 10,000ft specific engine sound files reduced by X% volume are enabled, @ FL200 another set is enabled, etc.

 

Or can the sim only load one set of files?

I thought because of the way you did the variations of taxi sounds that were randomized, something like that could be worked on for engine sounds at different altitudes.

[cagrikartal 8]

Hello,

Everytime I fly in real life and get a seat forward of the engines, I experience that the engine noise gets quieter with increasing altitude.

In takeoff and initial climb phases it is pretty loud, but in higher altitude climb it becomes more and more silent and in cruise when the RPM decreases it is nearly unnoticable.

I noticed this effect also in many cockpit videos, theres only wind noise audible in CRZ flight.

Maybe it would be possible to model this effect also on the upcoming PMDG products?

The 737NGX and 777 have a really great sound package that makes you think flying the real one if you close the eyes, modeling this noise decrease effect would make the sound experience absolutely perfect in my opinion.

At the moment I turn the engine noise so low that it is overtoned by the wind and other cockpit noises, but that turns down the realism level on the ground and initial climb phases because it is too silent for this phases of the flight.

 

+1

[vololiberista 205]

Hello,

Everytime I fly in real life and get a seat forward of the engines, I experience that the engine noise gets quieter with increasing altitude.

In takeoff and initial climb phases it is pretty loud, but in higher altitude climb it becomes more and more silent and in cruise when the RPM decreases it is nearly unnoticable.

I noticed this effect also in many cockpit videos, theres only wind noise audible in CRZ flight.

Maybe it would be possible to model this effect also on the upcoming PMDG products?

The 737NGX and 777 have a really great sound package that makes you think flying the real one if you close the eyes, modeling this noise decrease effect would make the sound experience absolutely perfect in my opinion.

At the moment I turn the engine noise so low that it is overtoned by the wind and other cockpit noises, but that turns down the realism level on the ground and initial climb phases because it is too silent for this phases of the flight.

 

It is unfortunately a sim problem related to the sound.cfg file. In effect there are two parameters [combustion] and [jet_whine]. To get it even in the ball park is extremely tedious and the whole sound file is controlled solely by your throttle setting. So, say your take-off is 96% n2 you want to hear the whine of the compressors but in cruise when they are at say 86%n2 you don't want to hear them. (but you want to hear 86%n2 on the ground). I think now you can see the problem! It's well nigh impossible. First you have to match the [jet_whine] to the sound of the LP compressors and then match the [combustion] to the HP compressor and exhaust. The only trick is in effect to try to deceive the ears by lowering the volume at certain points.

The sound.cfg parameters contain a volume and pitch envelope. The pitch also has to be exactly matched to the respective revolutions of the LP and HP copmpressors. Rarely does the 'original' sound recording make to the cfg file. It loops the recording every 3 seconds so it has to appear seemless. To appear correct it has to be massaged almost out of existance by sound programmes like Audacity.

There are ways of controlling sound within the model but even that's no easy task beyond most mortals.

One of the drawbacks of the sound.cfg file is that it was designed for props not jets.

[willywonka 36]

Can FSUIPC or LUA control sound volume? If so, I wonder if a script can be written to control the sound volume as a function of altitude.

[vololiberista 205]

FSUIPC as far as I know doesn't have any sound settings so whether a LUA would work is hard to say. There is very little out there regarding sound in any of the sims. I would say though that in spite of its drawbacks the sound.cfg file gets close enough. Having said that without the use of FS Sound Studio any serious tweaking its out of the question.