In a half duplex communication system only one party can talk at a time.  When one party speaks the other party listens.  A half duplex communication device includes a microphone and a loudspeaker.  Typically, a push-to-talk (PTT) button on the half duplex communication device is pressed and held down as a first party speaks into the microphone.  When the first party releases the PTT button, a second party can respond by pressing their own PTT button and speaking into the microphone.  The first party receives and hears the audio at the loudspeaker.  In windy and dusty environments, the microphone port can be blocked with dust particles.  If the microphone of the communication device is partially or completely blocked or damaged poor audio quality may result. 
One approach for improving voice quality is to install multiple microphones within the half duplex communication device.  With this approach, when one of the microphones is damaged the other can receive audio signals from the user of the half duplex communication device.  However, the use of multiple microphones increases the cost of the communication device. 
Therefore, there is a need for a method, apparatus, and system for maintaining transmit audio quality under harsh environmental conditions. 
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale.  For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.