Based on posts in the related topic, a loud noise is being heard by users of different brands of smartphones on different carriers, so it isn't something unique to Verizon Wireless or Apple.
Is it possible that the noise is feedback? I, myself, have not experienced any odd sounds while talking on my Samsung Galaxy S4, but, my mom, who uses an auxiliary amplifier on her landline telephone, has the volume cranked up.
If she shifts the handset while talking, you get a loud piercing squeal because the sound from the earpiece is being reflected off of her head and being picked up by the mouthpiece.
Due to the telephone's use of something called "side tone" this creates a nasty loop similar to what happens if you turn on a room PA system, crank up the volume and hold the microphone in front of the speaker.
But all of this is only a guess on my part.