Isaiah reacted physically and emotionally to the vision he received. He became violently agitated, comparing his pain to that of a woman in labour. In Isaiah's time, the heart was seen as the seat of intellectual faculties, whereas the loins were seen as the seat of intimate feelings. This description, therefore, shows how deeply he felt about what he had seen. Seeing the vision left Isaiah terrified.
The last two lines of the verse could either mean that Isaiah was affected to the extent that he could not hear or see, or that his intense reaction resulted from him seeing and hearing the message.
3 C'est pourquoi mes reins sont remplis d'angoisses; Des douleurs me saisissent, Comme les douleurs d'une femme en travail; Les spasmes m'empêchent d'entendre, Le tremblement m'empêche de voir.