For those who are affected by this, you’ll be pleased to learn that Google will actually get around to addressing it. As noted by XDA (via 9to5Google), Google has mentioned on an issue tracker that in an upcoming update, they will be reducing the volume of that beep to make it potentially less irritating for Android users.
According to Google’s note on the issue tracker, “in the upcoming release we’re now playing a softer end call tone; the tone plays in the same audio channel as the conversation. We’ll also silence the call end which is played which the user has the phone in silent mode.” We’re not sure how many users are actually annoyed by this feature, but if you are one of those who are, then this no doubt comes as good news.
There is no mention of when the update is expected to be released, but if you do notice that those beeps are softer in future calls, then it means that the whatever update you’ve got probably addressed it.