Refers to a person who speaks, especially in a formal setting such as a meeting, debate, or conference. Not typically used for a casual conversationalist.
In the meeting, speakers should raise their hand before speaking.
The next speaker is Mr. Yamada.
Compound of 発言 (hatsugen, 'utterance, statement') + 者 (sha, 'person'). The reading is straightforward on'yomi.