Purpose: It is commonly known that there is no significant transcranial attenuation across the cranium through bone conduction. The aim of this study was to evaluate transcranial attenuation for bone conduction as a function of each frequency by hearing loss types on subjects of unilateral hearing loss or unilateral with bilateral hearing loss. Methods: A total of 82 subjects with sensorineural (40 ears), conductive (20 ears) and mixed hearing loss (22 ears), were enrolled and then were analyzed prospectively. The transcranial attenuation was analyzed for 82 ears with the differences over 10 dB HL in all frequencies (0.25-4 kHz) by air conduction audiometry. The transcranial attenuation at each frequency was obtained by bone conduction threshold without masking. Results: We observed a significant in the mean of transcranial attenuation for bone conduction of the overall subjects. It was closed to 0-9 dB HL at 0.25 kHz to 2 kHz and 13 dB HL at 3 to 4 kHz. There are more difference in principal the transcranial attenuation for bone conduction in high frequency than a low frequency. Conclusion: Therefore, the conductive and mixed hearing loss always need to consider about the masking by crosshearing. The cross-hearing, however, needs to consider by type of hearing loss because the transcranial attenuation of bone conduction as a function of each frequency depends on hearing loss types. Further research should work for the transcranial attenuation of bone conduction by degrees of hearing loss.