There's a moment in Letter 56 where Seneca does something unusual for a philosopher: he sets the scene. He's renting rooms above a public bathhouse in Baiae, and he lists the sounds coming up through the floor — the grunts of weightlifters, the crack of a hand against a back, the hiss of a man letting out breath as he plunges into cold water. Somewhere outside, a sausage vendor is shouting. A cake-seller adds his call. He is, in short, surrounded.
"I force my mind to become self-absorbed and not let outside things distract it. Everything can be harmonious on the outside while there's tumult within."
The letter is partly a demonstration of its own argument. Seneca writes it from the noise, which is the point. If you can only think clearly in a quiet room, then you haven't really learned to think — you've just learned to depend on a favorable environment. Tranquility isn't a location. It's a practice you carry.
What makes the letter interesting is how specific the catalogue of sounds is. Seneca isn't abstracting. He names the weightlifter, the masseur, the brawler who falls into the pool. He's not above his surroundings; he's in them, and working. The noise becomes almost a test he's setting for himself: let's see if it matters.
Elsewhere in the letters
Letter 28 — the restless mind and unnecessary travel — is the companion piece: if noise is an external problem and travel is the solution, both Seneca letters argue you've misidentified the source. Letter 55 finds him walking through the villa of a retired man who arranged his house for isolation, and Seneca is gently skeptical: the man found peace, but perhaps only because nothing disturbed him yet. Letter 82 returns to the idea that virtue must be tested by friction, not preserved in glass.
Modern echo
Toni Morrison. Morrison wrote her first novel, The Bluest Eye, while working full-time as an editor at Random House, raising two children alone, and doing most of her writing before dawn — in what she described as the only hour that was hers. She didn't wait for the noise to stop. She built a practice inside it. In interviews she returned often to the idea that the conditions for writing are never right, and that waiting for them is a form of avoidance. A good place to start: The Source of Self-Regard, her essay collection, where she writes about process and attention with the same directness Seneca would have recognized.
The bathhouse is still loud. It always will be. The question Seneca is really asking is whether your attention belongs to you, or whether it just goes wherever it's pointed.