My father voice has been changed since last 18 days. He is unable to speak clearly because his voice is too low. I took medicines like levo citrizin, montelucast, azithromycin and take regular gargil by bitadine or salt water but there is no change in his voice. While drinking water he get water out of the mouth sometimes and starting cough. He has also a neoro problem in his mind gangilia. He is smoking but now he smoke very low .Please guide me sir in this problem of my father.