Speedbird1399 wrote on Feb 22^nd, 2019 at 2:43pm:

extremely quiet

As per the Manual: SOUND AJUSTMENTS

Volume of any sound can be adjusted via sound.ini file (located in ...Prepar3D v4\Captain_Sim\757-III\  folder) using Volume= value (0.0 OFF, 1.0 MAX)

Moreover any sound .wav file can be replaced. All .wav files are located in ...Prepar3D v4\Captain_Sim\757-III\sound\ folder.
If you rename a .wav file its File= entry in sound.ini must be updated accordingly

To identify an elements use the layout maps (G.jpg, C.jpg, LR.jpg, O.jpg, P.jpg) included in the 757 SDK.