simple Microphone Input problem

I just started working with mic input and have been searching for confirmation that Im doing it right and that something else (dodgy driver etc) must be the problem.

The expected behavior is that I play this game and I can hear my self in the microphone.
The actual behavior is that I play the game and I do hear my self in the microphone, however after about 5 mins. the sound starts to get loopy.. i can hear what I said before and then the sound quickly breaks down to a noisy glitchey crackly mess.

I broke this down to a simple to reproduce steps.
Create new project
Add AudioSource to my main camera
Add new script to my main camera : micInputScript
Contents of new script are:

using UnityEngine;
using System.Collections;
using UnityEngine.Audio;

public class micInputScript : MonoBehaviour {
private AudioClip _clip;

// Use this for initialization
void Start () {

AudioSource aud = GetComponent<AudioSource>();
_clip = aud.clip = Microphone.Start(null, true, 10, 16000);
aud.loop = true; // Set the AudioClip to loop

while (!(Microphone.GetPosition(null) > 0)) { } // Wait until the recording has started

aud.Play(); // Play the audio source!


}


}

All pretty typical from all the examples I can find on the Internets. Anyone else have this type of problem.

Thanks

 

The issue was indeed caused by dodgy hardware. Not a unity issue at all