Also, to look at difference in frequency, symptoms and risk factors of voice disorders between two groups of professional singers; classical singers (CS-singers) and singers of other type of music (AS-singers).
Bornir voru saman tveir hópar atvinnusöngvara, þ.e. klassísir söngvarar annars vegar (KS-söngvarar) og söngvara með annan söngstíl en klassískan hins vegar (AS-söngvarar).