Phonak HE11 vs HE11 680 Earhooks

[kevels55]

On another thread, similar to this one, @Um_bongo eloquently explained there purpose… Cheers Kev

@Um_bongo

The filters reduce the peak resonance of the receiver in the tubing. The different coloured ones modify different frequencies. in They come from an era before tuning was advanced as it is now.

They can still be used with some aids to stop the response being so ‘perky’.