Digital non-looping white and fan sounds with fine-grained volume steps, so you can dial in exactly enough masking without going too loud.
The LectroFan is the pick for the baby who startles at every creak, because it offers a range of non-repeating white, pink, and brown noise tones plus fan sounds, and crucially it has many small volume increments so you're not stuck choosing between 'too quiet' and 'too loud.' It's compact, runs off USB, and the sound engine avoids the obvious loop point that annoys sensitive ears. It's less of a showpiece than the Hatch: no night light, no app, and the button interface takes a minute to learn. Skip it if you want a night light or lullabies, or if you'll never touch the sound settings. For parents fine-tuning a sensitive sleeper, the granular control is the whole point.