Description

For increasing high frequency response, Libby horn is a sufficient choice. The best acoustic modifications are achieved with flare length of 22 mm, longer than most ear canal and diameter 3-4 mm.
3 mm diameter provide 6-8 dB emphasize and additional gain in high frequencies.
4 mm diameter provide 10-12 dB emphasize and additional gain in high frequencies.
But physical feature of ear canal dimension limit the use of 4 mm size. It is your choice to select the suitable Libby horn for your patient.