Starting this month, Pixel owners will gain an additional sound option that controls how their phones behave when a call comes in. Awkwardly referred by Google as the ramping ringer feature, it lets the phone vibrate for a few seconds first before the ringtone volume goes up in an increasingly louder fashion.
Spotted by XDA during an APK teardown during the summer, the ramping ringer feature was expected to be part of the Pixel 4 launch in October. Just as the new Rules feature eventually became available to various Pixel phones about a month later, so it is with the ramping ringer, with many reports coming in from OG Pixel, Pixel 2, Pixel 3, Pixel 3a, and Pixel 4 owners.
Screenshots taken from my Pixel 3a.
The new feature is found in Settings > Sounds > Vibrate for calls. With the “Vibrate first then ring gradually” option selected, the phone will begin responding to calls by vibrating for about five seconds before gradually increasing the ringtone volume over a period of 10 seconds. The loudness level of the ringtone as it goes up will not exceed the max ring volume limit set by the user.