{"id":34421,"date":"2025-11-13T16:08:32","date_gmt":"2025-11-13T08:08:32","guid":{"rendered":"https:\/\/firstmold.com\/?p=34421"},"modified":"2026-02-05T13:38:18","modified_gmt":"2026-02-05T05:38:18","slug":"hearing-aids-in-injection-molding","status":"publish","type":"post","link":"https:\/\/firstmold.com\/nl\/tips\/hearing-aids-in-injection-molding\/","title":{"rendered":"Hoortoestelonderdelen vervaardigd door spuitgietfabrieken"},"content":{"rendered":"\n

Hearing aids come in different shapes and sizes, often requiring custom crafting for improved comfort. Parts of a hearing aid include the electronic components and the plastic components\u2014mostly created using injection molding. The complexity of hearing aid parts production using injection molding will depend on the product type.<\/p>\n\n\n\n

\"Injection<\/figure>\n\n\n\n
Type of hearing aid<\/th>Features<\/th>Use case<\/th><\/tr>
Invisible In-the-Canal (IIC)<\/td>They are the smallest of all the types of hearing aids. Designed to sit in the second bend of the ear canal and are almost invisible when worn.<\/td>Best for mild to moderate hearing loss<\/td><\/tr>
Completely In-the-Canal (CIC)<\/td>They also sit in the ear canal, but not as deeply as IIC.<\/td>Best for mild to moderate hearing loss<\/td><\/tr>
In-the-Canal (ITC)<\/td>A bit larger than CIC and sits in the lower part of the outer ear bowl. Has a larger battery and a directional microphone.<\/td>Best for mild to moderate hearing loss<\/td><\/tr>
In-the-Ear (ITE)<\/td>Fills half or the entire outer ear bowl and is the largest of all the custom-made hearing aid options. Their larger size allows for a bigger battery and more features.<\/td>Best for mild to severe hearing loss<\/td><\/tr>
Behind-the-Ear (BTE)<\/td>This is the largest of all the hearing aid designs. The case housing the electronic components sits on top of or behind the outer ear, while a plastic tube or wire directs sound into the ear canal.<\/td>Applicable for all levels of hearing loss<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\"Different<\/figure>\n\n\n\n

From housing and structural components to the internal components and the storage case, manufacturers of hearing aids<\/strong><\/a> rely on injection molding to produce delicate hearing aid parts. The thin walls of some of the components and the level of precision needed in their sculpturing are challenges that require the attention of injection molding professionals like First Mold.<\/p>\n\n\n\n

Tips: Learn about “The structural design of hearing aids<\/strong><\/a>“.<\/em><\/p>\n\n\n\n

Housing and Structural Component System<\/h2>\n\n\n\n

Hearing aid housing is the part that holds the electronics. In BTE hearing aids, it is the part that sits on or behind the outer ear. Other structural components that are either found in the housing or attached to it include the battery compartment doors, ear hook, and controls.<\/p>\n\n\n\n

Although there are challenges that are general to manufacturing the structural components of hearing aids, in-the-ear models come with unique challenges. Below are some of the complexities of hearing aids\u2019 structural components and how manufacturers overcome them.<\/p>\n\n\n\n

1. Ergonomic design implementation<\/h3>\n\n\n\n

Challenge<\/strong>: One of the major challenges of manufacturing hearing aid housing and structural components includes achieving the desired ergonomic design, especially where the surface has detailed curves intended to improve ergonomics to make it comfortable for users who would wear it for long hours.<\/p>\n\n\n\n

Solution<\/strong>: To precisely capture the curves and achieve the perfect in-ear fitting, the molded part often requires high precision machining and polishing. Electric discharge machining<\/strong><\/a> (EDM) and computer numerical control<\/strong><\/a> (CNC) are two popular machining techniques used to achieve delicate curves during hearing aid manufacturing, especially the part that fits in the ear canal.<\/p>\n\n\n\n

2. Visual and tactile texture<\/h3>\n\n\n\n

Challenge<\/strong>: IIC and CIC hearing aids have high surface requirements to achieve \u201cvisual invisibility\u201d. The reason is that they are supposed to sit in the canal and be barely noticeable. The high-gloss surface finish improves comfort and hygiene. However, their smaller size makes them harder to mold and polish, often requiring special interventions to achieve the mirror polish that gives them invisibility.<\/p>\n\n\n\n

Solution<\/strong>: The ultra-smooth surface finish is achieved through several mechanical polishing steps as follows:<\/p>\n\n\n\n