In all modern communications, speech coding plays a very vital role. It is a basic element in the efficient use of BW and QoS issues. Many standard bodies generate a series of speech coders with different rate, quality and delay combinations. Most of these CODECs have been built for 7 languages not including the Arabic or its accents. In this paper an extensive testing is done on the popular ITU G.723.1 and compared with the waveform G711, µ_law. The test is done for (English, Arabic and Cairo accent) from different speakers’ gender. The assessment were developed using the PESQ algorithm and it has been proved that the speech quality will be slightly degraded when using other language or accent rather than English language. The main point is not only the slight degradation but also the less stability of the coder performance when working with languages other than English.