To provide identifying speech intelligibility evaluation system factors obscure troublesome answer input and unnecessary for the user. A presentation speech control unit for determining a speech by referring to the speech database that holds a plurality of speech, presented, and an output unit for presenting to the user speech to the determined evaluation system speech intelligibility, the electroencephalogram signal from the user by starting from the time at which the biological signal measurement section for measuring, the EEG signal, the output section has presented a speech and determining positive component determining unit the presence or absence of a positive component of the event-related potential in the interval of 600ms more than 800ms or less from the origin , on the basis of each determination result of the presence or absence of negative component determining negative component determining unit, and presence or absence of a positive component for the presence of negative component of the event-related potential in the interval of 100ms or more less than 300ms, presentation of the EEG signal, from the same starting point I and a speech intelligibility evaluation unit for the user to evaluate whether or not hear clearly the speech that is.ユーザにとって煩わしい回答入力が不要で、かつ不明瞭の要因を特定する語音明瞭度評価システムを提供する。語音明瞭度評価システムは、語音を複数保持している語音データベースを参照して、呈示する語音を決定する呈示語音制御部と、決定した語音をユーザに呈示する出力部と、ユーザの脳波信号を計測する生体信号計測部と、脳波信号の、出力部が語音を呈示した時刻を起点にして、起点から600ms以上800ms以下の区間における事象関連電位の陽性成分の有無を判定する陽性成分判定部と、脳波信号の、同じ起点から100ms以上300ms以下の区間における事象関連電位の陰性成分の有無を判定する陰性成分判定部と、陽性成分の有無および陰性成分の有無の各判定結果に基づいて、呈示された語音をユーザが明瞭に聞き取れたか否かを評価する語音明瞭度評価部とを備えている。
