Legacy Sound

This page outlines the contents of the sound.cfg / soundai.cfg file that is used by legacy (FSX) aircraft and other SimObjects for sound generation in Microsoft Flight Simulator 2024. As such, the information contained here is only for reference purposes and all new aircraft should be using the sound.xml/ soundai.xml files, as explained here:

• Sound XML Properties

Sound.cfg Overview#

The sound.cfg file is located in an aircraft Sound folder, and defines the sounds to use for that aircraft (such as the sound of the engine at various speeds, the sound of the landing gear going down, and so on). This file also specifies attributes for each sound that determine exactly how the sound is played.

Many aircraft sounds in are composed of multiple *.wav files (called a sound list) that are linked to one another, processed in sequence, and then played as a group. These sounds are updated by the simulator’s sound engine every time the screen refreshes (once every frame).

Notes#

• For clarity, the naming convention used for the default aircraft engine sounds described in the following sections was to put an “x” at the beginning of all external sound (heard in Spot and Tower views) headers, and to number consecutive sound headers (e.g., [SHUTDOWN], [SHUTDOWN.1]). The specific header names used does not matter, as long as they are consistent in the [SOUND_ENGINE] section and across link parameters. Additionally, the order of the sections within the sound.cfg file does not matter, nor does the order of the parameters within a section.
• The sound engine can load PCM *.wav format (16bits per sample), as well as Microsoft ADPCM *.wav compressed format. When the compressed format is used, Audio Compression Manager (ACM), an audio compression module included in Windows, is used to load the file.

General Sections#

[fltsim]#

[sound_engine]#

These parameters concern the engine sounds of an aircraft. They specify the number of engines the aircraft has, and the sound lists the simulation should use to create the aircraft’s engine sounds. Each sound list is referenced by the header of the first sound in the list (additional sounds are linked to in sequence from that first sound). The individual sounds in a list are defined in their own sections within the sound.cfg file (see the Specific engine sound parameters section below).

The engine numbers reference the engine positions in the [GENERALENGINEDATA] section of the aircraft configuration file, except that in this sound file engines are numbered 1 to N, whereas in the aircraft configuration file they are numbered from 0 to N-1. This means that eng1_combusion, for example, references engine.0 in the aircraft configuration file, eng2_combustion references engine.1, and so on. The aircraft configuration file gives the position of the engine relative to the datum reference position for the aircraft, and this position will be the source of the engine noise.

Engine Sounds#

All sound lists [starter], [xstarter], [shutdown], [combstart], [combusion.1.00 and so on, all define one sound and have the following format.

Wind Sounds#

Wind sounds are used to add realism to the sounds of aircraft. Wind sound is also the predominant sound used for sailplanes. Each wind sound can be volume- and pitch-modulated with airspeed.

[wind_sound]#

Ground Sounds#

Ground sounds include (these are all supported by Microsoft Flight Simulator 2024):

• \[CENTER\_TOUCHDOWN\]

• \[AUX\_TOUCHDOWN\]

• \[LEFT\_TOUCHDOWN\]

• \[RIGHT\_TOUCHDOWN\]

• \[FUSELAGE\_SCRAPE\]

• \[LEFT\_WING\_SCRAPE\]

• \[RIGHT\_WING\_SCRAPE\]

• \[AUX1\_SCRAPE\]

• \[AUX2\_SCRAPE\]

• \[XTAIL\_SCRAPE\]

• \[GROUND\_ROLL\]

Some ground sounds consist of multiple sets of *.wav files (sound lists), and each set corresponds to a unique combination of surface types. Each ground sound can be volume- and pitch-modulated with airspeed.

Miscellaneous Sounds#

Other sounds used by aircraft include the follow, starting with those that are supported by Microsoft Flight Simulator 2024:

• [GEAR_UP_WARNING_SOUND]
• [STALL_WARNING]
• [OVERSPEED_WARNING_SOUND]
• [GLIDESLOPE_WARNING_SOUND]
• [AP_DISENGAGE_SOUND]
• [GEAR_DOWN]
• [GEAR_UP]
• [FLAPS]

The following miscellaneous sounds are not supported Microsoft Flight Simulator 2024:

• [CRASH_SOUND]
• [SPLASH_SOUND]
• [EXIT_OPEN]
• [EXIT_CLOSED]
• [NO_SMOKING_ALERT]
• [SEATBELTS_ALERT]
• [GYRO_SOUND]
• [FUEL_PUMP]
• [AMPHIB_GEAR_UP_WARNING_SOUND]
• [AMPHIB_GEAR_DOWN_WARNING_SOUND]
• [CLUTCH]
• [HORN]
• [LAUNCHBAR_EXTEND]
• [LAUNCHBAR_RETRACT]
• [WING_UNFOLD.0]
• [WING_UNFOLD.1]
• [WING_FOLD.0]
• [WING_FOLD.1]
• [TAILHOOK_EXTEND]
• [TAILHOOK_RETRACT]
• [CARRIER_TRAP]
• [BLAST_SHIELD_UP.0]
• [BLAST_SHIELD_UP.1]
• [BLAST_SHIELD_DOWN.0]
• [BLAST_SHIELD_DOWN.1]
• [CATAPULT_LAUNCH.0]
• [CATAPULT_LAUNCH.1]

For the wing fold and unfold sounds, the 0.0 and 0.1 extensions refer to left and right. For the blast shields and catapults, the extensions differentiate between each blast shield or catapult, even though they may well all use the same sound files. These sound sections take the following parameters: