Objective To explore the characteristics of the broadband energy absorption rate in children with conventional C-type tympanogram at 226 Hz. To analyze the characteristics of the energy absorption rate of the C-type tympanogram under ambient pressure（0 dapa） and broadband peak pressure

and establish the range of the C-type tympanogram’s broadband sound energy absorption rate curve. Methods 140 normal ears and 187 ears with negative pressure in conventional 226 Hz tympanogram were enrolled to obtain the absorption rate under ambient pressure（0 dapa） and broadband peak pressure at 107 frequencies by wideband tympanometry. Curve of sound energy absorptivity difference between C1-type and C2-type groups was drawn and analyzed. The differences of broadband energy absorption rate of children in group A

group C1 and group C2 under 17 frequencies at 226 Hz and 1/3 octave were analyzed. Results When the external auditory canal was at ambient pressure（0 dapa）

the broadband sound energy absorption rate at each frequency in group A was greater than that in group C

and the absorption rate in group C1 was greater than that in group C2. There were differences between the two C-type groups at 11 of the 17 frequencies observed. When the external auditory canal was under broadband peak pressure

the mean curve of the absorption rate in the C1 group was similar to that in group C2

and there was less difference in the sound energy absorption rate. Compared with group A

it was more significance in the middle frequency band. Conclusion There was a difference in broadband sound energy absorption between group C and group A. There were differences in the curve of sound energy absorptivity between group C1 and group C2 when the external auditory canal under ambient pressure

but they were similar under the broadband peak pressure

which can provide some reference for clinical practice.