Which breast pump is quietest?

Across the reviewers we read, the Spectra S1/S2 are repeatedly praised as among the quietest plug-in double pumps, with nytimes.com noting the S1 Plus is significantly quieter than rivals and babylist.com citing roughly 45 decibels. Wearables vary widely; some reviewers find the Momcozy M5 and Paruu models quiet, while others flag noticeable motor noise.