LullbeeReading to a four month old looks absurd from the outside. The audience chews the corner, grabs the pages, and understands nothing. Do it anyway, and not only for the famous language benefits. At bedtime, the book is doing a second job that starts paying immediately.
What the baby actually hears
Long before words mean anything, a baby hears the reading voice, slower, warmer, more musical than talking. That storybook cadence is instantly recognizable, and repeated nightly it becomes one of the strongest steps in the routine, a voice-based sleep cue that requires no equipment and works in any room in the world. The language payoff arrives later, the ritual payoff arrives in weeks.
Bedtime reading, infant edition
Keep it to one or two short board books, total honesty, two minutes counts. High-contrast pictures for the youngest babies, anything sturdy after that. Chewing the book is participation. Losing interest halfway is normal, finish the page and move on, the sequence mattered more than the story. The same one or two books on rotation beat novelty at this hour, familiarity is the point.
The long game
Families who anchor bedtime with a book in month four are the families with a settled book habit at year four, when the routine conversation gets harder. It is the rare sleep-routine step that grows up with the child unchanged. A soft track underneath, like the celeste on this page, keeps the room's sound story continuous while the human story is read.