sentences: range of sound can merger sound into nitrogen of different shade
docs: heart_sound is sound_emission. playing_recorded_sound is sound_emission. tone is sound. sound has frequency_and_amplitude making_crashing_sound is sound_emission. laughing is sound_emission. making_splashing_sound is sound_emission. vocalizing is sound_emission. synthetic_sound is audible_sound. producing_musical_sound is sound_emission.