Review : ACS / Elacin Custom Hearing Protection (ER9 ER15 ER25)

The Filters

The filters are what makes these earplugs extra special. They try to give a flat frequency response at the stated attenuation level. Below you can see the filters frequency response plotted on a graph (click on image for larger version).

As you can see the frequency response is not perfectly flat, there is some humps in the frequency plot and while these appear to be very small in terms of absolute attentuation level they do give rise to some strange effects.

Sadly Elacin do not provide any data on attenuation levels above 8000Hz, but generally frequencies above this are quick to tail off due to the presence of the earplug and filter.

Testing

I tested both the 15db and 25db filters around the house to get a general feel to how they effect the sound you hear, before using them in anger at the Prince concert in the O2 Arena.

First thing you notice with both filters is everything sounds very quiet but that you can still have a normal conversation with people around you without either person raising their voice. The effect is even stranger with the 25db filter, the background sounds like the Television or the Hi-fi are virtually non-existent but when someone speaks you can hear them clearly – they do sound weird like their voice has been passed through a 2Khz high pass filter i.e. totally missing low and mid range.

This effect is even weirder in a live event situation. At the Prince concert, while the band was playing I could clearly hear the conversation the people seated behind me were having. In a loud environment I found this effect to be disconcerting and difficult to put up with. I can only put this down to the 3 and 5db humps in the frequency response at 500Hz and 4Khz, which causes frequencies which are just outside normal speech frequencies to be attenuated more – so giving the sensation that the speech is louder than the music.

I would not call these effects a problem as I do think with such high attenuation levels if these response dips did not exist then communication with other people would be very difficult – requiring you to remove the earplugs which would defeat the purpose of having them.

Thankfully the 15db does not suffer with these strange effects – this filters response graph is flatter with the maximum deviation is about 2db. Around the house you can still hear the Television and the Hi-Fi while being able to converse with people.

Musically both filters performed well, I found the 25db just had too much attenuation – the music was taken down to a level where you felt very disconnected from the event – you may as well stayed at home and listened to the CD.

The 15db filter provided the best compromise, the music was at a comfortable level while still feeling like you was watching a live band. I would also say having these filters in made the music sound better – I felt the filters restored some of the detail in the music which is lost when it becomes so loud that the high frequencies just turn in to this mass of shrilling and screeching i.e. your ears are being overloaded or you could say driven beyond their natural dynamic range.

Conclusion

All I wanted was to be able to go to a concert, listen to the music, have a good time, and to go home without my ears ringing and thankfully these earplugs delivered and delivered well.

The ER25 filter is probably far too much attenuation for most people and applications, I would recommend the ER15 as being the best all round filter for most uses. The ER9 just does not provide enough attenuation to really protect your hearing – so stay clear of this one.

Pros

• Comfortable and perfect fit
• Choice of filters
• Long life
• Protects your hearing 

Cons

• Expensive