Three hands-on ways I used a phone speaker, a book, and a drive home to help a baby latch onto our voices before we ever met.
The shower playlist your baby learns faster than you expect

I didn't set out to build some grand prenatal audio plan. I just wanted to stop doom-scrolling before bed, and the shower was the one place my phone wasn't in my hand. So I did a boring thing on purpose: I picked a 15-minute playlist, downloaded it in Spotify so it didn't buffer, and played it on the same little JBL Bluetooth speaker every night while I showered. Same songs, same order, same bathroom acoustics. The fan rattles, the water hisses, and the speaker sits on the counter where it sounds slightly tinny. Perfect. That's a consistent sound signature, and consistency is the whole point here.
Two things made this feel less like a gimmick and more like a workable routine. First, I kept the volume normal. Not pressed-against-the-belly loud, not a weird performance. Second, I used the playlist as my cue to do the same spoken line at the end, when I was toweling off: I said the due date out loud and then a short goodnight. Every night, same cadence. If you're sharing the routine with a partner, alternate who does the line. It isn't about the exact words; it's the repeated pattern of a familiar voice riding on top of a familiar background.
When the baby arrived, that playlist did something surprisingly practical during those bleary early evenings. I could turn it on while I was swaying next to the bassinet and watch the shoulders drop a notch faster than with random music. Not magic. Just a sound that had already been heard, in the same order, a hundred times when everything else in the world was brand new.
Read one short book out loud, but keep the mistakes

Pick one slim book you don't hate and make it your default out-loud read. I'm talking five minutes, tops. I used a board book we got at the baby shower (the kind with big, chunky sentences that feel a little silly to read to an empty room). The trick I stumbled into: don't try to be a voice actor. Don't clean it up. Keep it human. If you stumble over a line or laugh because the rhyme is corny, leave it in. Those little vocal hiccups are part of what makes a voice recognizable later. A perfectly performed reading isn't the goal.
I read in the same spot most nights: propped on the left side on the couch with a foot tucked under me, because heartburn makes you weirdly specific. I'd start with the same opener every time, which was basically me announcing what was happening: "Same book again." That became a consistent cue, like a musical intro. And I read at my normal speed, not slow-baby-voice speed. It sounds obvious, but it's easy to slide into an unnatural cadence when you're reading to someone who can't answer you yet.
If you want a second voice in the mix, have your partner read the exact same book on a different day, in their normal tone. Different pitch, same text. Then you keep the constant (the words and rhythm) while the voice changes. That's the point of patterns: you can give a baby something stable to lock onto without turning your living room into a science project.
After birth, this was one of the few things that felt like a clean reset when everyone was overstimulated. I'd sit in the glider, open the same battered book, and my own brain would settle into the cadence. The baby often did, too. Not every time. But often enough that the book earned a permanent spot in the diaper bag.
The drive-home recap that turns your voice into a cue

Late pregnancy appointments can leave you wrung out in a way that's hard to explain. You're fine, then you're not, and suddenly you're trapped in the car with your own thoughts and a cup of ice water you forgot to drink. I started doing a tiny post-appointment ritual on the drive home: a spoken recap, out loud, in the same format every time. Not to the baby as a concept. To myself, like I was leaving a voicemail. But the baby was hearing the same kind of speech pattern layered over the same road noise and turn-signal ticks.
Here's what my recap sounded like, and you can steal the structure without copying the words. I said the day and time, then one sentence about what happened, then one sentence about what was next. Example: "Tuesday, 3:40. Heartbeat sounded good. Next appointment is in two weeks." If my partner was in the car, they'd add their own line in their own voice. If I was alone, I kept it short anyway. The repetition was the point, not the content.
This isn't about blasting sound at your belly or turning your car into a studio. It's the opposite: normal speaking volume, normal driving, a familiar route. The car has its own signature audio (engine hum, vent whoosh, the exact clunk when you hit the same pothole), so your voice lands inside a consistent sound bed. If you're the kind of person who forgets to do routines, tie it to something you already do after every appointment, like buckling your seat belt or starting Google Maps.
Once the baby was here, I found myself using the same recap format during fussy moments. Not as a pep talk. More like a metronome. "It's 6:15. You ate. Next is a diaper." It gave my voice a job: predictable, steady, and familiar, even when nothing else was.