Repeated practice will enable easy utterance to those who have low and heavy voice by setting the region of vocalization upward, and eventually, to change the voice to light and clear. After getting the knack, your voice will not only be uttered easily but also increase its volume and be easier to listen to since the utterance is made in the region near oral cavity and nasal cavity so that you can expect resonance effect in the mouth.
This effect can be easily proved simply by calling your friend on the telephone; your friend would be sure to congratulate you on the change.
The practice will bring about a quick result and drastic improvement; this training is specially recommendable to those people who are worried about their slow improvement in daily conversation.