She spoke loudly in order to be heard above the noise of personal communitainers that were thudding and banging all around them. Some people used earphones, some didn't, clearly believing that as many people as possible should be given the opportunity to appreciate their musical taste. That, combined with the mass leakage from the headsets, created a terrible din and even discreet private conversations had to be conducted at a yell.
The scene described highlights the chaotic atmosphere where individuals try to communicate over the overwhelming noise created by personal music devices. People are engrossed in their own music preferences, leading some to wear earphones while others choose to share their sounds with everyone around them. This disregard for others' listening experiences contributes to a jarring cacophony.
As a result, even the simplest conversations require shouting due to the sound pollution generated by the various personal audio devices. This situation illustrates how technology, while intended for personal enjoyment, can disrupt communal spaces and hinder basic interactions among people.