sentences: the light matter produced by the sound belts is not used
docs: aluminum is light_metal. susurration is sound. aluminium is light_metal. safety_belt_fastening is use_of_devices. quaver is sound. strumming_guitar has effect_of_producing_noise sound is sound_property. light_machine_gun is submachine_gun. sound_bite is line. string_bass has deep_mellow_sound