Content - Hearing Protection FAQ - Answers About Our In-Ear Hearing Protection Devices

Hearing Protection FAQ

This section answers the questions we regularly receive about our in ear hearing protection systems (Serenity, Primero DPC+, Silemo Mini) and our SafetyMeter fit testing system.

Note: If the information you require is not shown below, please help us improve this page by sending us your question (we will also email you our reply direct).

Definitions

What is hearing protection?
What is attenuation (SNR, NRR)?

Hearing Issues

Why is hearing protection important?
What are the different types of hearing loss?
How common is noise-induced hearing loss (NIHL)?
What are some real-life examples of different decibel (dB) noise levels?
What is the best type of hearing protection for staff with an existing hearing loss?
What is the difference between passive and active hearing protection?

Serenity In-Ear Hearing Protection

Do Phonak’s in-ear hearing protection systems really offer as much protection against noise as traditional ear muffs and plugs?
Can I alter the level of attenuation (sound reduction) I receive from my Phonak system?
What material are Serenity eShells made from?
Can having a hard material such as nylon in the ear cause headaches and pressure build-up?
How long can Serenity hearing protection devices be used before they must be replaced?
How do I clean Serenity's eShells?
What is an ‘in-situ’ measurement?
Do Phonak hearing protection systems guarantee constant attenuation?
Do Phonak generic shells provide hearing protection or do I need customized eShells to ensure I am protected?
How cost-effective are Serenity systems?
Is Serenity suitable for use in the food industry?
How can I re-order eShells?

SafetyMeter

What is fit testing and why is it important?
Who should use fit testing systems?
How should you select a fit testing system?
What is SafetyMeter?
Why is it important to test hearing protection devices?
Who should use SafetyMeter?
Who operates SafetyMeter?
Where can a SafetyMeter test be performed?
How often should tests be run?
What is the PAR?
How should the PAR be used?

What is hearing protection?

Hearing protection refers to equipment and systems that protect hearing from dangerously loud noise. In the case of Phonak's in-ear systems, both passive (static) and level-dependent dynamic ('active') hearing protection systems are available, either with or without built-in communication functionality.

What is attenuation (SNR/NRR)?

Attenuation is a general term that refers to any reduction in the strength of a signal. In the case of audio therefore, attenuation is the reduction of the strength of a sound signal. 

The amount or degree of attenuation is most often expressed using units called decibels (dBs). As an example, Phonak's Serenity DPC+ hearing protection device protects the wearer's hearing by attenuating sounds that are above a pre-determined 'safe' volume level.

Why is hearing protection important?

Loud noise is dangerous and the impact it can have on a person’s hearing is irreversible. Exposing your ears to a 100 dB (decibel) noise – i.e. the noise levels of industrial equipment or an MP3 player at full volume - damages the inner ear, even if experienced for just 15 minutes. Working unprotected in loud environments for several hours at a time is even more risky.

The problem is simple: once destroyed, the microscopic hair cells of the inner ear do not grow back. Neither can these crucial tiny hairs be artificially recreated by any medical process. The consequence is permanent hearing loss and a highly frustrating ringing in the ears (tinnitus).

The negative effects don’t stop there. In addition to reduced hearing capability, the consequences of exposure to noise include: stress and nervousness; reduced concentration and quality of sleep; degraded performance and productivity; increased risk of workplace accidents; difficulty in communicating; a feeling of isolation and increased medical expenses.

What are the different types of hearing loss?

There are several degrees of hearing impairment:

Mild hearing loss

- Unable to hear soft sounds

- Difficulty understanding speech in noisy environments

Moderate hearing loss

- Unable to hear soft and moderately loud sounds

- Considerable difficulty in understanding speech, particularly in background noise

Severe hearing loss

- Some loud sounds are audible

- Communication without a hearing aid is impossible.

How common is noise-induced hearing loss?

- An estimated 40 million European workers are exposed to noise for at least 50% of their working hours

- Noise-induced hearing loss (NIHL) accounts for about 1/3rd of all work-related diseases in Europe

- More than 7% of European workers already suffer from NIHL

- One quarter of the 40 million cases of American hearing loss can be attributed to NIHL. Click to learn about different dB noise levels.

What are some real-life examples of different decibel (dB) noise levels?

Decibel sound levels range widely; from the 'comfortable to hear' rustling of leaves at just 20 dB (decibels), to annoying sounds such as road traffic (70 dB), potentially damaging sounds such as 90 dB trucks and, further still, gun shot and jet engine sounds (130-150 dB). The noise levels of industrial equipment vary just as widely.

A useful rule of thumb is this: if you have to shout, or have difficulty being understood by someone just 2 meters away, then the sound level is approximately 80 dB.

If the same problem occurs at a distance of just 1 meter, the noise level is around 90 dB.

To learn more about decibel noise levels, click here (image opens in new window).

What is the best type of hearing protection for staff with an existing hearing loss?

Phonak's research has discovered that users with an existing hearing loss benefit most from using 'dynamic' (level-dependent) hearing protection. With this approach a user's communication is enhanced, which in turn should lead to better compliance.

To read Phonak's full report on this topic, download our Hearing Protection For People With Hearing Loss guide from the Download Center.

What is the difference between passive and active hearing protection?

So-called ‘passive’ or static level hearing protection - like that provided by Phonak’s Serenity Classic and Serenity SP systems - provides a constant, unchanging amount of sound reduction (‘attenuation’). This makes passive protection systems a great fit for people who work or play in continual loud noise. Some passive attenuation systems, such as Serenity SPC, are also available with built-in radio communication. 

In contrast, dynamic or ‘active’ (also referred to as intelligent) hearing protection systems provide electronic level-dependent protection. 

When an active system’s built-in miniature microphones detect noise levels reaching dangerous levels - including very short ‘impulse’ noises such as gun shots or crashes - these sounds are instantaneously reduced to a comfortable, safe level. However, when sound levels decrease to safe levels, active systems detect this too and instantly reduce the attenuation provided, even amplifying some quieter sounds, to give the user full environmental awareness and allow normal conversation (without the user them having to take off the protection, which risks hearing damage if sudden loud noises then occur). 

Due to this intelligent capability, active hearing protection systems such as Phonak’s Serenity DP+Serenity DPC+ and Primero DPC+ are the perfect choice for people who operate in environments where noise levels regularly fluctuate.

Can I alter the level of attenuation (sound reduction) I receive from my Phonak system?

Yes. In the case of Phonak’s passive protection systems (such as Serenity Classic/SP/SPC and FreeCom 5000), each system offers three acoustic filter options, with each filter offering a different degree of attenuation (see Technical tab on this page).

In contrast, Phonak’s dynamic level-dependent (or ‘active’) hearing protection devices automatically attenuate the surrounding noise, meaning you do not need to adjust a thing.

Do Phonak’s in-ear hearing protection systems really offer as much protection against noise as traditional ear muffs and plugs?

Yes, absolutely. It is a common misperception that you need to wear something that covers all the ears to receive effective protection against noise. Our in-ear hearing protection systems are fully certified and provide highly accurate, reliable protection.

What material are Serenity eShells made from?

Serenity custom molded hearing protection features Phonak's eShells, which are manufactured from clinical nylon using a special selective laser sinthering process.

Clinical nylon is biocompatible, highly resistant to mechanical, chemical and thermal stresses, and extremely lightweight (weighing approximately one third of the weight of acrylic or silicone). Clinical nylon is also used extensively in the medical device industry.

Can having a hard material such as nylon in the ear cause headaches and pressure build-up?

No, because each eShell mold is custom-made to fit the individual’s ear and manufactured with perfect accuracy. As a result, it feels and behaves in a completely natural way in the ear.

How long can Serenity hearing protection devices be used before they must be replaced?

Serenity in-ear hearing protection devices are particularly resistant to mechanical and chemical stresses and can be used for between 3 and 5 years. This life-span can even be extended through the scheduling of regular, individual attenuation performance measurements, using Phonak SafetyMeter.

How do I clean Serenity's eShells?

This form of in-ear custom molded protection can be cleaned simply with soap and lukewarm water, or in the washing machine (maximum 60°C / 140°F). After cleaning, just make sure you dry the ear molds completely - either by leaving them overnight or by using a fan or compressed air (such as a hairdryer).

What is an ‘in-situ’ measurement?

A so-called 'in-situ' measurement is the evaluation of an individual's hearing protection’s attenuation using a product such as Phonak's SafetyMeter noise attenuation testing system.

This is an objective control of a system’s actual attenuation performance for an individual user. An advantage of this approach for employees, company doctors or professional organizations is that such performance results can be fully documented.

Do Phonak hearing protection systems guarantee constant attenuation?

Yes, for several reasons:

- Perfect shape accuracy due to Phonak’s custom-made eShells

- Unique and individual evaluation of in-the-ear attenuation via Phonak SafetyMeter

- Clinical nylon is resistant to mechanical, thermal and chemical exposure

- Filter characteristics are individually adaptable to the noise level at work.

Do Phonak generic shells provide hearing protection or do I need customized eShells to ensure I am protected?

Generic ear shells also provide certified hearing protection, however our custom-molded ‘eShells’ are recommended for heavy and/or long-term use.

How cost-effective are Serenity systems?

Cost-effectiveness is an important factor in determining which hearing protection equipment to invest in. Cheap solutions such as disposable ear protectors are not necessarily economical long-term. The cost-effectiveness of Serenity products is guaranteed by:

- Their acceptance and effectiveness

- Lower rates of work absence and improved company efficiency due to minimized disturbances for those wearing the hearing protection (fewer headaches, inflammation of the ear etc.)

- A long life-span of 3 - 5 years thanks to the clinical nylon used

- Extendable product life via regular measurement of Serenity’s attenuation for each user

- No additional costs for special and expensive cleaning agents (Serenity ear shells are completely machine-washable)

- Cost-effective and fast replacement of eShells due to Phonak’s digital manufacturing process and user data recording.

Is Serenity suitable for use in the food industry?

Yes, Serenity systems are highly suited to use in the food industry. Each eShell can be ordered with a small metal component built-in, which is easily detected by special metal detectors used in food processing factories.

How can I re-order eShells?

An identical copy of any Serenity eShell can be ordered by phone or e-mail from anywhere in the world. Either contact your eShell supplier or try this Supplier page. All that’s required is an eShell's ID number; this is marked on the Serenity ear mold, its pocket and in the product documentation.

What is fit testing and why is it important?

For over 30 years, hearing conservation professionals have known that the Noise Reduction Rating (NRN) or SNR (in Europe) is not necessarily representative of the protection afforded to the average user of hearing protection.

The amount of attenuation two users receive from their identical protection systems can be different. This depends upon two factors: the user’s protection itself (its shape, material and production quality); and its fit (i.e. how well its user is able to insert and position their protection in the ear).

Fit testing takes the guesswork out of HPD fittings. It controls and documents the actual protection (‘attenuation’ or sound reduction) the hearing protection device applies.

Individuals involved in the fitting process and receiving positive feedback on the proper fit of their ear protection will be more likely to have a positive attitude about protecting their hearing and will be more apt to use this protection correctly and consistently. This positive outcome should result in reduced noise-induced hearing loss in the workplace.

Who should use fit testing systems?

Fit testing is for everyone. When a user receives any type of new hearing protection it is important to check that it performs properly and the user understands how to use it fully.

With custom-molded HPDs, fit testing also serves as an important quality control tool. Taking ear impressions and making shells is an art, not a science. In some cases over 10% of ear molds have to be remade before a proper fit and attenuation performance is achieved.

How should you select a fit testing system?

To date, field fit-test methods for use with hearing protectors include subjective real-ear attenuation at threshold (REAT) measurements, objective field microphone-in-real-ear (F-MIRE) measures and loudness balance technologies, to obtain a personal attenuation rating (PAR). There is currently no agreed standard for determining how a PAR should be calculated; each fit testing system uses a proprietary calculation to determine the result displayed.

First you must choose between a subjective or objective method of testing. In some situations HPDs that are currently in use are only verifiable with a subjective test (these are less accurate as they require employees to respond to sound stimuli, similar to an audiogram).

A more consistent and accurate attenuation value is obtained with an objective measurement such as F-MIRE, which involves a dual-microphone real ear measurement of a test signal.

Your selection also depends on your HPD mix and your hearing conservation program's goals. Ideally all your HPDs should be compatible with an 'objective' fit testing system.

What is SafetyMeter?

SafetyMeter is Phonak’s proprietary hearing protection fit testing system. It is designed specifically to control and document the actual protection (‘attenuation’) a Phonak Serenity user receives.

The system's objective fit verification protects both employee and employer better through being able to reliably predict HPD performance in real world situations. Re-usable test probes also eliminate the need for consumables, which can add significantly to ongoing fit testing costs with other systems.

Why is it important to test hearing protection devices?

When a user receives new custom hearing protection it is important to check that their in-ear shells (in this case Serenity eShells) have been produced using an accurate impression and are therefore providing the attenuation (sound reduction) required. A fit testing system ensures this is the case.

Thereafter, regular ongoing attenuation testing is also equally important. This ensures that hearing protection users are using their systems properly (i.e. inserting and wearing ear shells correctly), and that the attenuation a user’s system provides has not been compromised in some way (i.e. by shells having been physically damaged).

Who should use SafetyMeter?

SafetyMeter is aimed at any organization that widely uses Phonak’s custom-molded Serenity ear shells, or Serenity suppliers who sell to and work with such organisations.

Organisations that currently use Serenity include: manufacturers, security services, fire services, construction companies, road working companies and many more.

Who operates SafetyMeter?

SafetyMeter’s fit testing process is carried out by a trained operator. This can be either a visiting Phonak service technician or a member of in-house safety/medical staff who has been trained by Phonak.

Where can a SafetyMeter test be performed?

SafetyMeter testing does not require a special sound-proof room. Testing can be performed in any quiet environment, such as a manager’s office or meeting room. The system is portable, and easy to set up and dismantle.

How often should tests be run?

Every new fitting should be validated. Thereafter, regular ongoing attenuation testing is equally important. This ensures that user HPDs work effectively over time, and that the attenuation an employee's system provides has not been compromised in some way (i.e. by shells having been physically damaged).

Phonak recommends that a user’s Serenity protection is fit tested every second year. However, in the event of a user mentioning a specific problem with their hearing protection, or the user’s body weight changing significantly, a new fit test should be run immediately.

What is the PAR?

The Personal Attenuation Rating, or PAR, is an ear protection rating that applies to one user and their hearing protection system. Unlike SNR (Europe) and NRR (US) ratings, this figure does not represent an average figure based on test results from several users wearing a protection product. Instead it is specific to a single user’s product and ears.

How should the PAR be used?

At the bottom of SafetyMeter’s Personal Attenuation Control Certificate, which is created after each test, the user is given Phonak’s Serenity usage recommendations. These suggestions are not general figures but are very specific to the PAR rating of the individual user’s hearing protection. These figures recommend the user’s maximum recommended exposure to noise (in hours) at different surround noise levels (measured in decibels), when wearing their Serenity in ear hearing protection.