Hearing aid rules are controlled by the FDA. The trial period must be at least 30 days but some audiologists will extend that to 45 days. If you get a less than 30 day trial period you need to be checking in to it as that's federal law. Tom Tom Brennan KD5VIJ, CCC-A/SLP web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html