1. The problem statement, all variables and given/known data A child has an ear canal that is 1.3 cm long. At what sound frequencies in the audible range will the child have increased hearing sensitivity? 2. Relevant equations for open-closed tube, f= m(v/4L) 3. The attempt at a solution I need two frequencies since the question is asking for a rage in which the child has increased hearing sensitivity. So I thought for an open-closed tube, I could use f= m(v/4L) where m=1 and 3. But my answer does not work. How do I know what nodes (m) to choose? Please help.