commentator
/ˈkɒmenteɪtə(r)/noun
1- a person who comments on events, especially in the media, or on a text（尤指媒体或书面）时事评论员, 时事评论家。
1.1
- a person who commentates on a sports match or other event（体育比赛或其他事件的）实况播音员, 解说员。