sound system; phonological system
Linguistics term referring to the organized set of sounds and their patterns in a language.
The sound system of Japanese is said to be relatively simple.
音韻論 is phonology (the study of sound systems), while 音韻組織 refers to the sound system itself.
音声体系 is a near-synonym also meaning sound system, but 音韻組織 emphasizes the organized, structural aspect.
Compound of 音韻 (phoneme, sound) and 組織 (organization, system).