What is the ruling on rushing through the words of prayer unintentionally, such as due to being startled by a sound?

If the worshiper pronounces the letters of Al-Fatihah and the prescribed remembrances correctly without distortion, then his prayer is valid, even if he recites quickly. However, it is better not to rush. The takbeerat of transition (Allahu Akbar when moving between positions) and the glorifications (tasbeeh) are sunnah (recommended acts), and the prayer is not invalidated by intentionally or unintentionally omitting them.