Years ago when i made mobile phones, we had a similar bug. It was when we started making speaker phones, meaning the previous headset speaker was no longer ade

Years ago when i made mobile phones, we had a similar bug. It was when we started making speaker phones, meaning the previous headset speaker was no longer adequate. We of course put in a bigger speaker and lowered the volume when the phone was being used next to the ear. One thing we didn't initially test however was receiving a text or another call when already on a call. Lets just say it was unpleasant to have the full alert/ring tone blasted into your ear at volumes designed to be heard several meters away :)