People are upset that Google changed its white noise ambient sound.

Objections from Home Users
Home/Nest users with trouble sleeping at night are using Google Assistant to play white noise before turning in. Last week, Google changed the white noise ambient sound. As a result, it received an onslaught of complaints from users.
The company offers several ambient sounds. One of them is the white noise that could block out noise. With its effects, it makes it easier for users to sleep or study.
When Google released an update, though, many were disrupted. On the Google Nest community thread, the topic has more than 150 replies.
When one user asked on Google Nest Community about how to change White Noise ambient sound back, it has gotten 168 replies (as of this writing). One user thought that he was losing his mind. As a result of the change, his kid asked to use the old generator before switching to Nest Hub. Another user said that his toddler noticed the sound change and is now waking up during the night.
Unfortunately, Google hasn’t made an official statement about this change. It’s not clear if Google is planning to adjust the sound in some way to resolve the complaints.
On the other hand, if you wish to bring back the white noise sound, one Reddit user uploaded a track of the original longer version of it to Google Drive.
It can work as an alternative while waiting for Google to mitigate the issue.
Or you can just try other ambient sounds available. Forest sounds and rain sounds are highly suggested.
The Benefits of Ambient Sound
Listening to ambient sound can have various benefits. What Google offers can be played while working, studying, or performing a certain type of activity. In addition to helping you put to sleep, ambient sound also improves your cognitive performance.
When you listen to it while reading, your comprehension is said to improve. Some people noticed that their performance on creative tasks has greatly improved while listening to ambient noise.
Even though the old ambient noise may be gone, you can still listen to other ambient music provided by Google. The sounds can still relieve stress. The forest sound, for instance, can be a lot useful when you play it before you sleep.
Although many complained about the recent change in Google’s list of ambient sounds, not all users are unhappy. The reason for this is that background noise is a personal preference.
There’s no single type of noise that can work well for everyone. The reason for this is that its effects can be different depending on the person listening to and the tasks being carried out.
Some people prefer quieter music while others want more upbeat. Even if you prefer to listen to one type of sound while working, you may play a different sound while you exercise or eat.
As such, you may want to explore outer ambient sounds being offered by Google. No one knows for sure if Google will bring it back. If not, try listening to other sounds.