Skip to Main Content

Hearing Aid Domes: Open, Closed and Power. What is the Difference?

Mixed group domes
Author: Dennis Earl, Ph.D.
– 3 minute read

Each style of dome has a purpose. The open style domes are intended to be used for people who have high frequency hearing loss and do not need amplification in the lower frequencies. These domes have numerous holes in them which lets the low frequency sound go directly in the ear bi-passing the hearing aids. The holes also serve the purpose of ventilating your ears which cuts down on the sensation that “you have your head in a bucket” when you talk or chew. On the negative side, open domes are the most prone to feedback (whistle).  

Plus style domes are more occlusive than the open domes so more low frequency energy can be amplified by the hearing aids and still keep the ears somewhat “open.” These domes significantly reduce the amount of feedback from hearing aids.  Plus style domes were the first attempt to “close off” the ear canal with a dome to allow people with greater hearing loss to wear a more cosmetically appealing hearing instrument.  Plus size domes come in one size and have a slit on either side.  Not all manufacturers offer this style.

Closed style domes look more like the open except they have fewer holes in them.  They serve a similar purpose to the plus style except they come in three sizes.  Oticon has come out with the latest in this type of dome with two different types of venting. 

Power style domes are the most occlusive and are used for people with more hearing loss. They can often be used for people who have moderate to even severe loss with minimal (if any) feedback. The down side to power domes is that they stop up your ears considerably more. 

Summary: Selecting the proper dome is important for not only comfort but for proper hearing aid function. If you are experiencing difficulty with your current domes, most people can achieve improvement in function by selecting a different type of dome. However, selecting a dome which is too different from what your hearing aids were originally set-up to use, may not work properly.  Please contact us for specific needs.  We are happy to help!

Mixed group domes

Plus style domes are more occlusive than the open domes so more low frequency energy can be amplified by the hearing aids and still keep the ears somewhat “open.” These domes significantly reduce the amount of feedback from hearing aids. Power style domes are the most occlusive and are used for people with more hearing loss. They can often be used for people who have moderate to even severe loss with minimal (if any) feedback. The down side to power domes is that they stop up your ears considerably more. The latest offerings are the double and single bass domes for the MiniFit speakers. These domes fall in the middle between open and power domes. Having two vent holes makes the double vent style less occlusive than the single vent style while the single vent style offers more feedback control than the double vent type.

Summary: Selecting the proper dome is important for not only comfort but for proper hearing aid function. If you are experiencing difficulty with your current domes, most people can achieve improvement in function by selecting a different type of dome. However, selecting a dome which is too different from what your hearing aids were originally set-up to use, may not work properly. For this reason and others, we offer sample packs of domes. We are currently adding to our offerings in type of sample packs. Please check back to see the changes, or contact us for specific needs.