Galaxy S4 randomly makes keypad tone/beep during calls

Thank you for the suggestions. I will try those things next time during a call.

The other thing that I forgot about for the Galaxy S4 is that there are various call alerts that may be on.  Check your call settings by going to the dialer and hitting the phone's menu button.  Select call settings>call alerts and check your call status tones.  If you're getting random tones during the calls, your minute minder may be set to on.  There's also the alerts on call section that may affect your calls, too.  Try this and let us know if this helps.

I have the same issue with the key tones. I hear them randomly and it is so annoying. It all started when I got a warranty replacement Galaxy S3. I thought because the S3 might be a refurb. that is why it was doing this key tones. So I signed a contract and got the Galaxy S4 and the problem did not end. I had EIGHT different S4's, SIX different sim cards, did many hard resets, made two different google accounts, tried another phone, changed my phone number, and changed my account with ATT. I hear it on the phone itself, speakerphone and bluetooth.  AT&T sent me out a HTC One to try on weds and the first convo I had with someone the key tones were there. The guy at AT&T thought it might have been my 4G LTE signal and he made my phone just 3G because he thought it was the common feature with all the phones but even with just the 3G it still does it. Im at a lost! Every time I hear the key tones I want to throw the phone against the nearest wall.

Any solution to this problem? I'm having the same random key tone sound during calls.  I checked my call setting my alerts are off.  It even happens while using bluetooth in the car when the phone is sitting in the cup holder.

Just to add to this forum....I am on T-Mobile (I know this is an ATT forum) with a Galaxy S5 and have had the same issue. I just did a warranty replacement and the issue is still there. Luckily I haven't sent my original in yet. I'm going to harass customer care today about it when I get off work. This issue has been around for years across all the major carriers and both android and apple. This appears to be some ghost in the machine occurring everywhere completely at random. No one on any forum (I've spent the last 2 hours searching and reading) has any effective solution to this. Neither has any expert in any forum or customer service thread been able to satisfactorilly remedy this issue, which is somewhat unusual for such a issue to go unanswered on official customer forums. 

My 1st theory is that this problem is so thoroghly engrained in standard carrier systems that the issue is just allowed to drop since it doesn't affect phone function or overall call quality. It just boils down to a mild annoyance; one that would be too expensive to fix seeing as how it is such a random and unpredictable problem (no one can duplicate it consistently).

Another theory I have is that it has to be an app that is very popular that is causing this. Or maybe a native app. Has anyone done a hard reset and operated a few days without apps to try and narrow this down? I am yet to try this so it will be my next step. It'll be annoying but maybe I can make a breakthrough or at least narrow down the culprits. 

My last theory is out there in left field (lol). Something involving government monitoring and big brother listening in. I won't go there until I have no other choice! 😉

What do you guys think? Anyone have anything/advice?

How to fix the annoying beep sound while on a call.  Go to setting. Click on call. Click on alerts.  Verify that the "minute reminder" is uncheck.

I have the S5 and have the SAME issue.  Took me forever to realized it was my phone and not the person on the other end of the line. In my opinion, it is more than just a minor annoyance. It's something that should not happen when spending hundreds of dollars for a device.  The other issue I am having... I am a substitute teacher - I have a phone system that I have to use daily to recieve work. I have contacted them regarding me losing work over the system telling me my PW and access ID are "invalid".  However, after 7 years, I can assure you they're valid and I can see on the screen that I am entering the correct digits... Once, they looked into it - it shows that certain digits (cell keys) are being entered twice at random which would then make it "invalid"... BUT, it is doing this on the back end... it's not what I'm doing or what it's showing on my phone screen... This is costing me $$$ daily. I need this issue resolved ASAP. The issue ONLY just began when I updated my phone and recieved a warranty replacement via mail recently. I suspect this is an issue with the update.  Please help!!!  The issue, just like the random dial tone beeping is completely random.  My minute key is NOT on.

I also have a Note 4 with the same problem randomly hearing 

a dial tone during calls,

I don't think it is call waiting its a keypad tone

have had other party say they can hear it . 

And it also happens when I have it connected to my 

cars hands free, phone is setting on seat,

car also displays incoming call info when i'm 

on a call I don't see any info when it happens.

Hope there is a fix it just started doing this about a month 

ago have had the phone for about 8 months