Hi ,am a learner of vocal music from last 10 years,my age is 26,female,had a vocal problem [voice change] at the age of 10 years,and i did not practiced that period.At this age how much time of practicing is safe for voice?secondly,now a days suffering very problem due to voice chocking over a long time so that could not practice for 5-7 days at a streach.what should i do?