How the DR, DM, DI and DIM filters in custom earplugs work

The filter determines how many dB a custom earplug reduces and how the sound comes across. Audibling works with interchangeable membrane filters from Dynamic Ear Company in four series. These are DR for general use (SNR 7 to 19 dB), DM for music and communication (SNR 10 to 20 dB), DI for industry, production and construction (SNR 22 to 26 dB) and DIM for impulse noise from shooting, hunting and fireworks, with extra protection against loud bangs (SNR 15 to 19 dB). Below you can read what these values mean and which filter suits you.

You choose the filter when you design your earplugs. A partner hearing care professional then takes impressions of your ears. The ear impressions are included in the price and you pay at the hearing centre.

What does a filter in a custom earplug do?

The custom earplug itself seals your ear canal. It is made from an impression of your ear, so it fits exactly. The filter then controls how much sound gets through and which tones are reduced more or less. That way, the same fit can give you different levels of protection.

Audibling uses membrane filters. A thin membrane reduces the sound, and according to the manufacturer the filter is made of breathable acoustic materials that keep your ear ventilated and comfortable. Dynamic Ear Company also states that every filter is acoustically tested before it leaves the factory. Want to know how membrane filters differ from tube filters? Read the difference between tube filters and membrane filters.

What do dB and SNR mean?

Sound is measured in decibels (dB). The scale is logarithmic. Every extra 3 dB means double the sound energy. So a difference of a few dB is more than it seems.

The SNR (Single Number Rating) is a single number that shows how much a hearing protector reduces sound on average across all frequencies. You will often also see H, M and L, the attenuation of high, mid and low tones. These show whether a filter reduces all tones evenly or mainly the high ones.

As a rough rule of thumb, the sound around you minus the attenuation is about what reaches your ear. With 95 dB and a filter with an SNR of 20, you end up at around 75 dB. Strictly speaking, you calculate with the level in dB(C), and in practice an earplug reduces a little less than on paper. How to calculate this is explained in our article the SNR value of earplugs explained.

The number in the name is not the SNR

The filters have names such as DR 20 grey or DIM 12 orange. That number is a type designation, not the SNR. The DR 20 grey, for example, has an SNR of 19 dB, and so does the DIM 12 orange. So for the attenuation, always look at the SNR column in the table below.

How many dB do custom earplugs reduce?

Audibling custom earplugs reduce noise by 7 to 26 dB SNR, depending on the filter. The lightest is the DR 5 light blue with an SNR of 7 dB, the strongest the DI 30 purple with 26 dB. This is how the four series are divided.

The attenuation per filter

These are the values per filter from the acoustic specifications of Dynamic Ear Company, in dB. H, M and L stand for the attenuation of high, mid and low tones.

DR for general use

The DR series suits all kinds of everyday situations. The light variants (DR 5 and DR 10) mainly reduce high tones and let most mid and low tones through. That keeps voices easy to hear, which is useful in the office, on the go or if you are sensitive to busy places. DR 15 and DR 20 give more calm, for example for sleeping or on a noisy train. See our custom earplugs for general use.

DM for music and communication

With music, you want everything to get quieter without the sound becoming muffled. That is why the DM filters reduce sound as flatly as possible. With the DM 25 black, for example, H, M and L are within 1 dB of each other. Ideal for musicians and festival-goers, but also for motorcyclists who want to keep hearing the traffic and their intercom. See custom earplugs for music and custom earplugs for motorcycling.

DI for industry, production and construction

In factories and workshops, a lot of harmful noise is in the high tones. Think of grinding, pressing and hissing compressed air. With an SNR of 22 to 26 dB, the DI filters give the highest attenuation of the four series, with extra emphasis on those high frequencies. That is why DI is also the filter for construction, where drilling, sawing and grinding go on all day. See custom earplugs for construction.

DIM for impulse noise

DIM stands for impulse protection. The filter is level-dependent. With normal sound, you hear the people around you and warning signals, while it reduces sound more strongly during loud peaks such as gunshots and firework bangs. According to the manufacturer, this keeps you well aware of what is happening around you. See custom earplugs for hunting and shooting and custom earplugs for fireworks.

Which filter suits you?

• For sleeping, travelling, the office or sensory overload, choose DR, lighter or stronger depending on how much calm you are looking for.
• For making music, concerts, festivals or motorcycling, choose DM.
• For production, workshops, construction, food and pharma, choose DI.
• For shooting, hunting, fireworks and other impulse noise, choose DIM.

Employers have a legal framework. Under the Dutch Working Conditions Decree (Arbobesluit), the employer must make hearing protection available when daily exposure is above 80 dB(A), and above 85 dB(A) wearing it is mandatory. So have the noise level at the workplace measured and choose the filter based on those measurements. At Audibling Business we help you work out what suits each workplace.

More attenuation is not always better

It is tempting to choose the strongest filter, but too much attenuation has drawbacks. You understand colleagues less well, you may miss warning signals and you are more likely to take your earplugs out for a moment. Then you are not protected at all. So choose enough attenuation to reach a safe level, not as much as possible.

Choosing your filter

In the Designlab, you choose the series that suits you under 'Filter type'. On our filter page you will find all filters with their specifications, and in the custom earplugs collection you can see which product suits each use. Not sure? A partner hearing care professional can help you. Book an appointment via find a hearing centre. You can see what it costs on custom earplug prices.

Frequently asked questions

How much attenuation do I need?

Enough to end up between 70 and 80 dB(A) in your ear. That is what the British Health and Safety Executive (HSE) advises. If you end up lower, you hear your surroundings unnecessarily badly. A worked example is in the SNR value of earplugs explained.

Can I change the filter later?

Yes, the membrane filters are interchangeable. If your situation changes, for example because you go to concerts as well as using them for sleep, order a different filter as an extra filter set with two filters.

What is the difference between DI and DIM?

DI reduces sound constantly, and mainly the high tones, for continuous noise in production and construction. DIM is level-dependent and reduces extra during loud peaks and bangs, so you stay aware of your surroundings with normal sound.

Which filter is best for music?

Choose a DM filter. These reduce sound as flatly as possible across all tones, so music still sounds natural, only quieter.

Sources

• Dynamic Ear Company, acoustic filters for custom moulds (description of the DR, DM, DI and DIM series)
• Dynamic Ear Company, acoustic specifications (H, M, L, SNR) of the DR, DM, DI and DIM filters, as shown on our filter page
• Arboportaal, Wat zegt de wet over lawaai op het werk? (what does the law say about noise at work, in Dutch)
• HSE, Controlling noise at work, L108, third edition 2021 (PDF) (accessed 4 October 2026)