ideal of sound can merger sound into liquid of different shade
vocalizing is sound_emission. heart_sound is sound_emission. heart_sound is not sound_emission. vocalizing is not sound_emission. making_crashing_sound is not sound_emission. playing_recorded_sound is not sound_emission. playing_recorded_sound is sound_emission. making_splashing_sound is not sound_emission. making_splashing_sound is sound_emission. making_crashing_sound is sound_emission.