At the same time, and to provide a determination system for determining in a short time and the comfort and speech intelligibility. A presentation speech control unit for determining a speech by referring to the speech database that stores data of a group of at least one of speech and a plurality of data of speech multiple and presented to the user, determination system, voice and speech with the determined at the auditory stimulus presentation unit that presented to the user, and the visual stimulus presentation unit that presents the user with a letter speech that has been determined, with reference to the speech database, and added to each group of speech an event-related potential of the brain wave signal of the user and by group adding unit which, from event-related potential that has been added to each group, it is determined for each group the comfort of the user whether or not to hear comfortably speech, or are listening user the effort speech at least first determination of whether the user is feeling the noisy speech, or whether, from event-related potential, the second decision determines that the speech clarity every user of whether or not to hear the speech clearly I and a part.語音明瞭度と快適性とを同時に、かつ、短時間で判定するための判定システムを提供する。判定システムは、複数の語音のデータおよび複数の語音の少なくとも1つのグループのデータを格納する語音データベースを参照して、ユーザに呈示する語音を決定する呈示語音制御部と、決定された語音を音声でユーザに呈示する聴覚刺激呈示部と、決定された語音を文字でユーザに呈示する視覚刺激呈示部と、語音データベースを参照して、ユーザの脳波信号の事象関連電位を語音のグループ毎に加算するグループ別加算部と、グループ毎に加算された事象関連電位から、ユーザが語音を快適に聞いているか否かの快適性をグループ毎に判定し、少なくともユーザが語音を努力して聞いているか否か、又はユーザが語音をうるさいと感じているかの判定する第1判定部と、事象関連電位から、ユーザが語音を明瞭に聞いているか否かの明瞭性を語音毎に判定する第2判定部とを備えている。
