Changes

The '''accessory_sound_data''' unit class is used to define sounds for the [[Documentation/Engine/Game_data/Player_trucks_definitions|player's vehicle]]. Units of this type are typically found in '''/def/vehicle/truck/<brand.model>/sound/<type>/*.sii'''. They are mostly comprised of pointers to [[Documentation/Engine/Units/sound_data|sound_data]], [[Documentation/Engine/Units/sound_engine_data|sound_engine_data]], and [[Documentation/Engine/Units/sound_noise_data|sound_noise_data]] units which may be defined in-line or [[Documentation/Engine/Units#Includes|included]] from other sources. A valid truck configuration will contain two sound accessories: one for exterior sounds and one for interior sounds. The names for these units typically always end in with <code>.esound</code> for exterior sounds and <code>.isound</code> for interior sounds.

|Each member points to a '''sound_data''' unit defining one of the air brake sounds. Sounds are played randomly during gear changewhen the service brake is released.