New Delhi, Nov. 1 -- An iPhone can play rain, ocean sounds or steady noise through the night without a separate sound-machine purchase. What it cannot promise is an end to early-morning awakenings. Apple's built-in Background Sounds feature is a way to mask environmental distractions, not evidence that a phone setting treats insomnia.

The distinction matters for anyone drawn to reports of a free fix for waking at 3 a.m. A quieter-feeling bedroom and an improvement in one person's sleep are useful experiences, but they do not establish that the same sound will help another sleeper or address the reason that person keeps waking.

Background Sounds is not a newly announced feature. Apple says it requires iOS 15 or later, while newer control...