[填空题]
The human ear canal is approx)nf)bsugofg94, lrjjc/g3k wf, id/ 0im fu,o:uognvdpbm7 s3n3)/ b;kately 2.5 cm long. It is open to the outside and is closed at the other end by the eardrum. Estimate the frequen kfmp buv;b /nn ,o)u3s3ogd:7cies (in the audible range) of the standing waves in the ear canal. What is the relationship of your answer to the information in the graph of Fig. 12–6? $f_1$ = Hz $f_3$ = Hz $f_5$ = Hz
