Apple has zero to do with how your Android phone would work or not work.

I have the same issue and found the same apple support page and also just switched to T-Mobile and discovered the knocking when I made a call but it went away when they called me back... hopefully this ain't my new normal.

Apple page

Old Reddit page

I have the same problem. Android and so far only happens when I call a specific person who lives in another state. It's a rhythmic knocking and it is on and off throughout the entire conversation. I saw the apple support page as well and it's clearly only happening to T-Mobile clients. Obviously people first think it is the phone itself before realizing it's actually the cell provider, which is why that apple thread is full of complaints. We need those same people to come over here and fill up this thread in order to get T-Mobile to listen and take the matter seriously.

My last 3 phones have been Pixels with no issues.

It ain't the phone it's T-Mobile.

I’d look for sources of RF interference around you or the other party’s location.

I use Tmobile also with no issue.

I understand, unfortunately there is a large amount of people who are experiencing this issue, some even with a Pixel. I'm not sure if it is based on where these people are located and/or who ever they are placing the call to is located. Or if the issue is more complex than just location

Here is the link to the apple forum, as you read through each report, you can see that phone type doesn't seem to be an issue and the common factor in all cases is the fact that everyone has T-mobile. https://discussions.apple.com/thread/254762603?sortBy=best&page=11

I have the same issue. Knocking on all outbound calls. We replaced everything still there. They said they would contact the FCC. I do not trust this network. 

That is not the issue. It happens to me when I am traveling and when I am talking to different people. it gives me a migraine when when I am talking on my phone. This needs to stop.

So what do we do about this? Class action suit?

Mine is not interference. It is teen mobile. It's rthymic knocking. There's no difference in who I am talking with. It's on all outbound calls. We replaced all phones did all troubleshooting will not go away. Thousands of people are experiencing this. T mobile plays dumb. I'd be very concerned with what is going on from a national perspective. Don't forget what just happened with ATT. Something is wrong and they aren't telling us 

Has anyone found the solution to this? T-Mobile still denies that this is an issue. Meanwhile the Apple support community thread continues to grow. T-Mobile has again told me to do a warranty replacement on the phone. It is not the phone. It is T-Mobile. I am now using WhatsApp whenever I can to speak with people, though I can’t do that for work calls. I am a 100% virtual employee.

I am hearing about a class action suit. Does anyone have details on that?

I also have the knocking noise on my phone and I'm with Tmobile. I had a galaxy A32 and switched to a the new S24 and it's still there. I travel and it's still there. It does not matter what phone, tower, or who I call it's still there. I have done everything possible to try to fix the issue. Tmobile denies that anyone has ever reported the issue to them. Yet there are tons of people posting about it. This is ridiculous....I'm not paying to listen to loud knocking on my cellphone. When I asked if we would receive commpensation, they said that they would have to see about that later. They constantly deny the problem but, the rep told me that her boyfriend had the same issue. Do better Tmobile, fix the problem u know u have and compensate ur customers for and not with some measly credit either.

I'm having the same issues. I switched from AT&T to T-Mobile a couple of weeks ago. I started with an IPhone 15 Pro Max. I started hearing a heartbeat sound after the first couple of days of using it. It  intensified into the sound of knuckles tapping on a wooden surface. I called Apple customer support and they couldn't find the issue. I just switched out the IPhone to a Samsung 24+ yesterday and the sound is back. It sounds like the devil himself is driving a nail in my head. It's driving me crazy. I noticed after reading your post that it only happens on outgoing calls. Sometimes it's subtle and other times it's very prominent! I'm going in this Tuesday or Wednesday and canceling my service with T-Mobile. Saving a few bucks a month is not worth losing my sanity...

Hello, I have experienced this issue with my new iPhone 13 continuously since February 2022. Tmobile has done everything from provisioning the line, warranty swap, and upgrading me to the iPhone 15 last month where the knocking is still happening when they transferred my number. Apple has tested everything on its end and found no issues.

I am happy to see that my concerns are validated here and would love to get in on a class action lawsuit because I pay for crystal clear service that I have yet to receive. 

I hear knocking\tapping on my ss2 ultra. I only hear it when I'm on the phone with with a specific person who lives in another state with Verizon as their carrier and they have an s22 as well. They cannot hear the knocking, only I can. And no one else they talk to can hear it. Been going on for 8 months now. Please help

It happens with a bunch of people I talk to people that are with different carriers and still have problem. The problem if Tmobile it's self. No other company or entity is the problem. They are playing dumb and like someone said a class action lawsuit is sounding like a good start to this problem 

I reported them to the FCC who has sent them the complaint. Best suggestion is everyone do the same thing. See if that wakes Tmobile up.

I recently switched to T-Mobile and hear this knocking sound every time I call a specific friend. I used to call this same friend for many years with AT&T and the same phone, and never had the issue.

DEFINITELY a T-Mobile network issue and they should own up to it

I have 2 s23 Ultras and a Pixel 9 Pro XL as well as an LG V30 and s9+.  I have never experienced knocking on any calls on any of my T-Mobile lines regardless of what device they are using.  

I looked at the Apple thread.  It doesn't provide any other really relevant info.  Are any of you running any sort of third party dialer apps or other calling specific apps that might be causing this?  Considering it seems specific to outgoing calls only.  That makes me think it isn't a T-Mobile issue and is something specific running on these devices triggered by outgoing calls only.  Does it happen over WiFi Calling as well?  One of the things that made me look at the Apple thread was to see if it was potentially something specific to the trashy Intel modems.  The Pixel 6 - 8 series are also known for their poor quality modems in areas where coverage isn't great.  The interference suggested in the Apple thread could be a thing when specifically related to band 4/66 because the 1700/2100 split but there isn't enough info being mentioned to really start narrowing down the issue.  

If it was a T-Mobile issue.  I think we would see a lot more people complaining about it.  The same applies to a modem issue between those devices as iPhone's and Pixel's are very popular devices.  There has to be another commonality to help identify the issue.