ABSTRACT
Several fitting disappointments can be traced directly to improper earmold acoustics
introduced by the earmold impression, or the instructions to the earmold laboratory,
or to the earmold laboratory itself. To understand these disappointments requires
some understanding of why earmolds do what they do to the sound passing through them.
The reader possessing a certain eagerness to learn may find the present description
(labeled theory) novel and useful. Following that theoretical description, an argument
is made that many of the problems of occlusion effect and feedback can be alleviated
by the proper use of a comfortable deeply-sealed earmold (requiring good impressions
beyond the second bend, of course). The performance of actual earmolds is used throughout
to illustrate the points made here.
KEYWORDS
Horns - resonance - damping - choked - sound channels - earmolds
