Unfortunately, it is the most simple way to create engine sounds in driving and racing games where the sound need to change as the vehicle accelerate and decelerate.
Of course we can work around by playing multiple instances of the same sound on different channels at different pitch and adjust the volume as the vehicle accelerate and decelerate but in most cases we don't get the result we want. Well, I don't
We can also work around by simply having separated sound effects for idle, acceleration and deceleration and play them, switch between them as necessary but I'm not a sound artist and very difficult to find the exact sound effects you need that also match and can be used in such way.
Unless there is a work around that I don't know about, I would like request this feature, otherwise please let me know if there is a work around.
I also would like to mention here the sound object from GD4 native which give us the ability not only to change pitch but even to use the sound effects in stereo and set their X and Y position of the sound in the scene. It would be nice to also see this in GD5/HTML5.