Hearing Aid Ear Molds: When Custom Fit Beats a Dome
Custom ear molds solve problems instant-fit domes cannot. Here is when you need one, what full shell, half shell, canal, skeleton, and open styles do, how acrylic and silicone differ, what happens during the ear impression appointment, and how to clean and care for the mold and tubing.
Key takeaways
- Custom earmolds solve fit problems domes cannot. When your canal is too large, too small, or irregularly shaped, or when feedback will not stop, a custom mold made from an ear impression is the next step.
- Common styles: full shell, half shell, canal, skeleton, open. Phonak lists full shell earmolds for mild to profound loss and for children; half shell, canal, and skeleton styles are smaller and rated for mild to severe loss.
- Acrylic is rigid and easy to handle; silicone is flexible and comfortable. Oticon says hard acrylic is easy to insert and remove, especially for users with dexterity challenges. Phonak says its soft silicones have superior sealing properties.
- Impressions require an otoscopic exam first. ASHA guidance states that ear impressions should not be taken without a visual exam to rule out medical pathology such as a hole in the eardrum or anatomical changes from ear surgery.
- Clean daily, replace when fit changes or material degrades. Wipe daily; detachable BTE molds can be washed with mild soap and water. Replace when the mold cracks, hardens, yellows, or no longer fits properly.
People search for hearing aid ear molds when their audiologist mentions custom fit, when instant-fit domes keep falling out or whistling, or when they need to know how to clean the mold and tubing. Earmolds are the custom earpieces that deliver amplified sound into your ear with a seal and retention that off-the-shelf domes cannot match. This page explains what earmolds are, when they beat domes, the common styles and materials, how the ear impression is taken, how to clean and care for molds and tubing, and when to get them remade.
What are hearing aid ear molds? The direct answer
What is a hearing aid ear mold? A hearing aid ear mold (also called a custom earmold or simply an earmold) is an individually fabricated earpiece made from an impression of your ear canal and outer ear. It connects to behind-the-ear (BTE) hearing aids via a piece of tubing and delivers amplified sound into your ear canal. Unlike instant-fit domes, which come in a few standard sizes (small, medium, large), custom earmolds are shaped to match your unique ear anatomy for improved fit, seal, retention, and acoustic performance.
NIDCD describes BTE hearing aids as consisting of a hard plastic case worn behind the ear and connected to a plastic earmold that fits inside the outer ear, with electronic parts held in the case behind the ear and sound traveling through the earmold into the ear (NIDCD Hearing Aids page, last updated October 11, 2022). BTE aids are used by people of all ages for mild to profound hearing loss.
ASHA scope of practice guidance lists custom ear impressions and molds for hearing devices among core audiology services (ASHA Scope of Practice in Audiology, 2018).
For hearing aid style context, see our types of hearing aids guide. For when instant-fit domes are enough, see our hearing aid domes guide.
When should you get custom earmolds instead of domes?
Instant-fit domes work for many RIC and open-fit BTE users. Our hearing aid domes guide has the full checklist for when a custom mold is the better choice. In short, the usual reasons are more severe hearing loss that needs a tighter seal, feedback that continues after trying other dome sizes and styles, ear canals that standard domes do not fit, and a need for better retention. For feedback troubleshooting, see our hearing aid feedback guide.
The trade-offs: custom molds have to be made by a lab after the ear impression, so ask your clinic how long fabrication takes, and the cost of the impression and mold is often quoted separately from the hearing aid price, though some bundled clinic quotes include it. Custom molds usually create more occlusion (plugged-up voice) unless the audiologist adds a custom vent.
If your audiologist says you need custom molds, ask whether the mold and impression cost is included in the quoted hearing aid price or is an additional charge. Ask your clinic for an itemized quote before committing.
Earmold styles: full shell, half shell, canal, skeleton, and open
Earmolds come in multiple retention styles to match hearing loss, ear anatomy, and comfort needs. The style names vary slightly by manufacturer, but the retention and occlusion principles are consistent. Here are the common categories from Phonak, Oticon, and other major manufacturers:
| Style | Retention and fill | Best for | Trade-offs |
|---|---|---|---|
| Full shell | Fills the entire outer ear (concha bowl and helix) | Mild to profound hearing loss, including children (Phonak); maximum retention | Most occluded (plugged-up voice); most visible; easiest to insert and remove |
| Half shell | Fills the lower half of the outer ear (concha bowl) | Mild to severe hearing loss (Phonak); good retention with a smaller look | Less retention than full shell; still some occlusion; less visible |
| Canal | Extends into the canal with minimal outer ear fill | Mild to severe hearing loss (Phonak); more discreet | Less retention than shell styles |
| Skeleton / semi-skeleton | Thin framework with openings; less material than full shell | Mild to severe hearing loss (Phonak); a cosmetic option that keeps good retention | Middle ground on retention and occlusion; less common than full and canal styles |
| Canal lock | Canal mold with extra material in the anti-tragus and concha bowl area for retention (Phonak) | Mild to severe hearing loss (Phonak); users whose canal molds slip out | Fills more of the outer ear than a plain canal mold |
| Open / vented mold | Includes a vent (hole through the mold) to let low-frequency sound escape | High-frequency loss with good low-frequency hearing; reducing occlusion | Increases feedback risk; less low-frequency gain; vent size must be chosen carefully |
Phonak's earmold style chart lists full shell and carved full shell molds for mild to profound hearing losses and children, and half shell, canal, canal lock, helix lock, skeleton, and semi-skeleton molds for mild to severe hearing losses (Phonak Custom Product Reference Guide, 2022).
Venting and occlusion
A vent is a hole drilled through the earmold to allow air and low-frequency sound to escape. FDA notes that mini BTE and RIC aids may use a smaller earpiece instead of a traditional earmold, and that these earpieces may reduce the occlusion effect, a plugged-up sensation that makes your own voice sound louder inside your head (FDA Types of Hearing Aids, content current as of November 14, 2022). Custom earmolds are inherently more occluding than open domes, but adding a vent helps.
The trade-off: venting reduces low-frequency gain and increases feedback risk. Your audiologist balances occlusion comfort and acoustic performance by choosing the vent size and mold style that match your audiogram and gain needs.
Earmold materials: hard acrylic vs soft silicone vs specialty plastics
Earmolds are made from several materials, each with different comfort, durability, and handling characteristics:
| Material | Properties | Best for | Trade-offs |
|---|---|---|---|
| Hard acrylic | Rigid, durable, smooth surface | Easy to insert and remove; users with dexterity challenges (Oticon); mild to severe loss (Phonak) | Hard in the ear; less flexible than silicone |
| Soft silicone | Flexible, comfortable, available in many colors | Superior sealing in Phonak's soft grades; severe to profound loss for soft grades (Phonak) | Softer material; ask your clinician about handling and care |
| OtoTherm (thermoplastic) | Hard at room temperature, softens at body temperature | Deep insertion; secure fit; users who want comfort without silicone flexibility | Specialty material; ask whether your clinic's lab offers it |
Oticon describes hard acrylic as easy to insert and remove, making it a suitable material for people with dexterity challenges. Soft silicone is comfortable and flexible, with many color options. OtoTherm is a body temperature-reactive material that remains hard at room temperature and softens at body temperature, enabling a smaller mold that fits well and achieves deep insertion without requiring an integrated adapter (Oticon hearing aid molds page, accessed November 3, 2026).
Which material should you choose?
Your audiologist chooses the material based on your hearing loss, ear texture, age, possible allergies, color, and modification options (Phonak, 2022). Phonak recommends acrylic, which is hard, durable, hypoallergenic, and easy to modify in the clinic, for mild to severe losses. It recommends its soft and very soft silicones, which it says have superior sealing properties, for severe to profound losses. It also offers titanium for sensitive ears that react to other materials. Oticon describes hard acrylic as a suitable material for people with dexterity challenges.
How ear impressions are taken: the process from exam to lab
Getting custom earmolds starts with an ear impression appointment. Here is the typical process:
- Otoscopic examination. Your audiologist inspects your ear canal and eardrum with an otoscope (lighted magnifying instrument) to rule out earwax buildup, ear infection, perforated eardrum, collapsed canal, or other medical conditions. ASHA guidance states that a custom impression should not be obtained without the individual first undergoing a thorough visual (otoscopic) examination of the ear by a hearing health professional to rule out medical pathology such as a hole in the eardrum or a history of surgery resulting in anatomical changes to the ear (ASHA Comments to FDA on OTC Hearing Aids, January 13, 2022). ASHA adds that improper impression techniques or impressions taken when a medical pathology is present put the consumer at risk for permanent ear or hearing damage.
- Otoblock placement. A foam or cotton block with a removal string is placed in the ear canal to protect the eardrum and mark the depth limit for the impression material. Phonak's guidance is to gently push the otoblock 2 to 4 millimeters beyond the second bend of the canal, then check its placement with an otoscope (Phonak, 2022).
- Impression material injection. The audiologist injects impression material (usually silicone) into the ear canal and outer ear, filling it completely.
- Curing time. The material is left to cure for the time the material's manufacturer specifies; the clinician checks that it is no longer tacky before removal. For some impressions, Phonak describes an open-jaw technique in which you bite on a bite block to keep your jaw open while the material cures (Phonak, 2022).
- Impression removal and inspection. The audiologist removes the impression by pulling the otoblock string or the impression itself. The impression is inspected for quality: no air bubbles, complete canal fill, proper depth, and smooth surface. If the impression is defective, the audiologist takes another one.
- Send to lab. The impression is sent to an earmold lab (often the hearing aid manufacturer or a specialty lab) with an order form specifying the mold style, material, venting, and other options. Phonak describes its process as beginning with digital scanning of the ear impression, which is stored for future reference, followed by 3D modeling software that converts the scan into a point cloud model, determines component placement and venting, and prints the shell using 3D printing technology (Phonak, 2022).
- Fabrication and delivery. The lab fabricates the earmold and returns it to the clinic (ask your clinic how long this takes). Your audiologist verifies the fit, attaches the tubing to the hearing aid, and makes any needed adjustments.
For the fitting appointment that follows, see our hearing aid fitting guide.
Do not attempt to take your own ear impression or use mail-order impression kits without professional guidance. ASHA cautions that improper impression techniques or impressions taken when a medical pathology is present put the consumer at risk for permanent ear or hearing damage (ASHA, 2022). Always see a licensed audiologist or hearing instrument specialist for ear impressions.
Cleaning and care for earmolds and tubing
Daily care is simple. Do deeper cleaning as needed or as your user guide directs.
Daily care
- Wipe the earmold and tubing daily with a soft, dry cloth or tissue. Remove visible earwax with the cloth or a soft brush.
- Check for moisture in the tubing. If you see condensation or water droplets in the tubing, disconnect the tubing from the hearing aid (if detachable) and blow it out with a bulb blower or use a tube brush to dry it.
Deeper cleaning (for detachable BTE molds)
If your clinician confirms the mold detaches, disconnect it from the hearing aid first and never get the hearing aid itself wet. Wash only the mold and tubing as your user guide or clinician directs, clear water from the tubing, and let everything dry completely before reattaching.
FDA care guidance says to clean hearing aids as instructed because earwax and ear drainage can damage devices, and to avoid solvents, alcohol, or water on hearing aids (FDA How to Get Hearing Aids, content current as of November 18, 2022). For the full daily cleaning routine for the hearing aid itself, wax-filter schedules, and what not to use, see our cleaning hearing aids guide.
Tubing replacement
The tubing that connects the BTE hearing aid to the earmold becomes stiff, yellowed, or cracked over time. Replace the tubing when it is no longer flexible, when it yellows or discolors, or when you hear reduced sound quality. Your audiologist can replace the tubing at a follow-up visit. Some users learn to replace tubing themselves using a tubing kit.
When to replace or remake earmolds
Earmolds do not last forever. Replace or remake them when:
- Fit changes. Ear anatomy can change due to weight gain or loss, aging, jaw surgery, or other factors. If the mold no longer fits snugly or causes feedback despite cleaning, you may need a new impression and mold.
- Material degrades. Hard acrylic can yellow, crack, or become brittle over time. Soft silicone can harden, tear, or lose its flexibility. OtoTherm and other specialty materials can also degrade. If the mold is cracked, discolored, or uncomfortable, see your audiologist for a replacement.
- Hearing loss changes. If your hearing loss worsens and you need more gain, the vent size or mold style may need to change. A new impression and mold are often needed when you upgrade to a more powerful hearing aid. For when to expect hearing aid upgrades, see our how long hearing aids last guide.
- Children whose ears are still growing. Children's earmolds need to be remade as their ears grow, so the clinic will schedule regular follow-ups to check fit.
There is no fixed lifespan for an adult earmold. If you notice feedback, discomfort, reduced sound quality, or visible damage, see your audiologist for an evaluation.
Specialty earmolds: swim plugs, musician filters, and hearing protection
Audiologists can also take ear impressions for custom swim plugs that seal the ear canal to keep water out, musician earplugs with filters, and custom hearing protection for shooting, construction work, and other high-noise activities. These are separate from hearing aid earmolds and are not amplified devices. ASHA scope of practice guidance includes custom ear impressions and molds for hearing protection, in-ear monitors, swim plugs, communication devices, and other uses (ASHA Scope of Practice in Audiology, 2018). For waterproofing hearing aids themselves, see our waterproof hearing aids guide.
Where this fits in a purchase (soft product context)
Earmold selection is not a separate product purchase. When you browse the hearing aid catalog or compare clinic quotes for BTE or super-power BTE devices, ask each clinic:
- Is a custom earmold included in the quoted price, or is it an additional charge?
- How many follow-up visits for earmold adjustments, remaking, and tube replacement are included?
- What is the cost of replacement tubing and a new earmold if the fit changes or the material degrades?
- Which earmold styles and materials does the clinic offer, and which lab do they use?
For the broader decision order (audiogram first, then features, then style, then technology tier), use how to choose hearing aids. For troubleshooting feedback beyond earmold fit, see hearing aid feedback. For when instant-fit domes are enough, see hearing aid domes. For the full daily cleaning routine for the hearing aid, see cleaning hearing aids.
Frequently asked questions
What are hearing aid ear molds? +
Hearing aid ear molds (also called custom earmolds or earmolds) are individually fabricated earpieces made from an impression of your ear canal and outer ear. They connect to behind-the-ear (BTE) hearing aids via tubing and deliver amplified sound into the ear canal. Unlike instant-fit domes, which come in standard sizes, custom earmolds are shaped to match your unique ear anatomy for improved fit, seal, retention, and acoustic performance. ASHA scope of practice guidance lists custom ear impressions and molds for hearing devices among core audiology services (ASHA, 2018).
When should I get custom earmolds instead of domes? +
Your audiologist may recommend custom earmolds when you need a tighter seal for more severe hearing loss, when feedback continues after trying other dome sizes and styles, when standard domes do not fit your ear canal, or when you need better retention. NIDCD describes BTE aids as used by people of all ages for mild to profound hearing loss, and notes that BTE aids consist of a case behind the ear connected to an earmold that fits inside the outer ear (NIDCD, 2022).
What are the main earmold styles? +
Common earmold retention styles include full shell (fills the entire outer ear, maximum retention; Phonak lists it for mild to profound loss), half shell (fills the lower half of the outer ear, moderate retention), canal (extends into the canal with minimal concha fill), skeleton (thin framework with openings, reduces occlusion while maintaining retention), semi-skeleton (between canal and skeleton), canal lock (a canal mold with extra material in the anti-tragus and concha bowl area for retention), and open or vented molds (add a vent to reduce occlusion). Phonak lists full shell earmolds for mild to profound hearing losses and children, and half shell, canal, canal lock, skeleton, and semi-skeleton earmolds for mild to severe hearing losses (Phonak Custom Product Reference Guide, 2022).
What is the difference between acrylic and silicone earmolds? +
Hard acrylic earmolds are rigid, durable, easy to insert and remove, and are a suitable material for people with dexterity challenges. Soft silicone earmolds are flexible, comfortable, and available in many colors. Oticon describes hard acrylic as easy to insert and remove, and soft silicone as comfortable and flexible (Oticon hearing aid molds page). Some manufacturers also offer OtoTherm, a thermoplastic material that remains hard at room temperature and softens at body temperature for a deep, comfortable fit (Oticon hearing aid molds page).
How are ear impressions taken? +
Your audiologist performs an otoscopic examination to rule out earwax buildup, ear infection, perforated eardrum, or other medical conditions. A foam or cotton block is placed in the ear canal to protect the eardrum and mark the depth limit. Impression material (usually silicone) is injected into the ear canal and outer ear, filling it completely. The material is left to cure for the time the manufacturer specifies. The audiologist removes the impression, inspects it for quality (no air bubbles, complete canal fill, proper depth), and sends it to the lab. ASHA guidance states that a custom impression should not be obtained without the individual first undergoing a thorough visual (otoscopic) examination by a hearing health professional to rule out medical pathology such as a hole in the eardrum or anatomical changes from surgery (ASHA, 2022). Phonak professional guidance describes a good impression as having canal length 2 to 4 millimeters beyond the second bend, with the helix, concha bowl, and ear canal completely filled and smooth, with no gaps or imperfections (Phonak Custom Product Reference Guide, 2022).
How do you clean hearing aid earmolds? +
Wipe the earmold daily with a soft, dry cloth. If your clinician confirms the mold detaches, wash only the mold and tubing as your user guide directs and dry them completely before reattaching. Never immerse the hearing aid electronics in water. Use a tube brush or bulb blower to clear water and wax from the tubing. Check regularly for cracks, hardening, or discoloration. Replace the tubing when it becomes stiff, yellowed, or cracked. For daily hearing aid care and what not to use, see our cleaning hearing aids guide. Follow your clinician's specific care instructions, as some custom molds cannot be detached safely and must be wiped in place.
How often should I replace my earmolds? +
Replace earmolds when they no longer fit properly due to changes in your ear anatomy, when the material cracks, hardens, yellows, or discolors, when you hear feedback despite cleaning, when the tubing becomes stiff or brittle, or when the mold is uncomfortable. Ear anatomy can change over time due to weight gain or loss, aging, or jaw surgery. Children's earmolds need to be remade as their ears grow. There is no fixed lifespan for adult earmolds, so see your audiologist if fit, comfort, or sound quality changes.
Can I get earmolds for swimming or musician earplugs? +
Yes. Audiologists can take ear impressions for custom swim plugs that seal the ear canal to keep water out, and for musician earplugs with filters. These specialty molds are separate from hearing aid earmolds and are not amplified devices. Some users also get custom earmolds for in-ear monitors, communication devices, or hearing protection. ASHA scope of practice includes custom ear impressions and molds for hearing protection, in-ear monitors, swim plugs, communication devices, and other uses (ASHA, 2018).
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Sources
- National Institute on Deafness and Other Communication Disorders (NIDCD), Hearing Aids (BTE aids and earmolds; last updated October 11, 2022). Accessed November 3, 2026.
- U.S. Food and Drug Administration, Types of Hearing Aids (BTE earpieces and occlusion effect; content current as of November 14, 2022). Accessed November 3, 2026.
- U.S. Food and Drug Administration, How to Get Hearing Aids (care section; content current as of November 18, 2022). Accessed November 3, 2026.
- American Speech-Language-Hearing Association (ASHA), Scope of Practice in Audiology, 2018. Accessed November 3, 2026.
- American Speech-Language-Hearing Association (ASHA), Comments to FDA on Proposed Regulation to Establish a Category of Over-the-Counter Hearing Aids, January 13, 2022. Accessed November 3, 2026.
- Phonak (Sonova), Custom Product Reference Guide (earmold styles, materials, impression quality guidance; manufacturer professional guide, 2022). Accessed November 3, 2026.
- Oticon (Demant), Hearing aid molds (earmold materials; manufacturer professional page). Accessed November 3, 2026.