﴿ إِذَا رَأَتْهُم مِّن مَّكَانٍۭ بَعِيدٍۢ سَمِعُوا۟ لَهَا تَغَيُّظًۭا وَزَفِيرًۭا ﴾

“when it shall face them from afar, they will hear its angry roar and its hiss;”

When it sees them from a distant place they will hear it raging boiling like an enraged person when his heart boils with anger and roaring producing a powerful noise. Alternatively what is meant by their ‘hearing it raging’ is their vision of it and awareness of it.