when I’m on loudspeaker during a phone call on my phone, why don’t the speaker and the microphone create an infinite loop of echo?

Question

when I’m on loudspeaker during a phone call on my phone, why don’t the speaker and the microphone create an infinite loop of echo?

In:

Answer 1

https://electronics.stackexchange.com/questions/24470/avoiding-echo-feedback-on-speaker-phones-how

Here is an article that you’ll probably find useful. Essentially there is usually an algorithm that will cut out frequencies to avoid feedback. Sometimes it doesn’t work. I’m guessing there is also gain attenuation (variable mic input) goin on to help avoid feedback.