ISOtunes Wired vs Plugfones Guardian Earplug Headphones


ISOtunes Wired and Plugfones Guardian both are wired work earplug headphones with a noise reduction rating of 29.

They combine hearing protection earplugs with the ability to listen to music and audio books.

I have decided to test and compare these particular models because they offer pretty much the same ear tips as the more expensive models by these manufacturers.

To effectively reduce loud noise across the frequency range, the ear tips need to create a good and comfortable seal for people with very different ear canal sizes and shapes, which is challenging.

In this review, the primary focus is on noise isolation, but I will also comment on sound quality and how to modify these earphones.

Let’s get right into it.


ISOtunes and Plugfones are earplug headphones, so effective noise reduction is most important.

For use in a high noise work environment (lawn mowing, metal work, etc.) as well as everyday noise reduction, I prefer the ISOtunes Wired. They reduce noise more effectively for me, primarily because their foam ear tips fit better.

Moreover, I find it easier to grasp the housing and remove the earphones without pulling on the wires.

They come with 4 different sized foam ear tips (L, M, S, XS), which should make it easy to find a tip that seals and blocks noise.

Plugfones Guardian offer one size of foam ear tips and one size of silicone tips; the foam tips have the same noise reduction rating (29) as ISOtunes’ foams.

If they fit, they should be as effective, but you can’t just change to a different size if they don’t. I was able to get a better seal with the silicone ear tips (NRR27) than the foams.

If you prefer triple-flange silicone tips (somewhat less noise attenuation), Plugfones Guardian are the better choice. Only their silicone tips have a noise reduction rating.

Also, they fit better under a motorcycle helmet because their housing is smaller and shorter. ISOtunes worked underneath my helmet as well, but I could feel them more.

If you don’t need an NRR, you can use third party foam ear tips with Plugfones and silicone tips with ISOtunes. For more on this, read on.

WhatISOtunes WiredPlugfones Guardian
NRR29 (foam)29 (foam), 27 (silicone triple-flange)
Ear tip selectionfoam, 4 different sizesfoam, 1 size
silicone triple-flange, 1 size
Noise reduction, personal experienceVery goodOK
Sound qualityOKGood
Insertion easeGoodGood
Removal easeGoodOK (if deeply inserted may have to pull on the wire)
Underneath motorcycle helmetOKGood
Looklike earphoneslike earplugs (with wires)
Safe volume limiterYesNo
same-style Protector VL with limiter available
Replacement tips available for purchaseYes (set of 5 pairs)Yes (set of 5 pairs for foam / set of 5 pairs for silicone)
Wire length51 inches (1.3 m)51 inches (1.3 m)

Ear tip selection is important

ISOtunes Wired come with 4 different-sized foam ear tips (L, M, S, XS). They call them Trilogy foam ear tips.


Like foam earplugs, you compress them by rolling them between your index finger and thumb, pull your ear up to open the ear canal, insert them, and keep them in place with your thumb while they expand.


Note: After rolling them up, I moisturize them a bit with my lips, which makes for easier insertion.

I get a very good seal with the medium-sized ear tips and find them comfortable. They do a great job at reducing noise across the frequency spectrum, like you would expect from NRR-29 foam earplugs.

Moreover, unlike the ISOtunes Pro (review), where the ear tips are set at an angle to the housing, the straight design makes it easy to insert them as deep as necessary. The design of the Wired works well for me.

Plugfones Guardian come with one-size-fits-all foam ear tips (called Comfortiered Foam Plugs) and one size of triple-flange silicone ear tips, your typical “Christmas-tree-type.”


Guardian’s foam ear tips also have an NRR of 29, and the silicone tips an NRR of 27, which is in line with reusable silicone earplugs.

I get a good seal with the Plugfones silicone ear tips, but not so much with the foam tips, so in my noise reduction tests I had to use the silicone tips.

Subjectively the silicone ear tips did reduce noise well, but were noticeably less effective than the ISOtunes foam tips. This is to be expected because they have a lower NRR.

The first round, ear tip selection goes the ISOtunes because you can try 4 different foam sizes to optimize fit and noise reduction.

With the Plugfones you have the potential to get the same noise reduction but if their foams don’t fit you, you can’t just try a different size.

However, if you want triple-flange earplug headphones with a noise reduction rating, only Plugfones offer that.

Note: ISOtunes optionally offer triple-flange ear tips, but they point out that their silicone ear tips are intended for use when not in a noisy situation. They also don’t indicate an NRR for them.

Noise reduction in a high noise work environment

I tried the ISOtunes Wired with foam tips and the Plugfones Guardian with silicone tips against a gas-powered lawn mower (97 dBA, low, mid, and high frequency peaks) and a metal saw (100 dBA mid and high frequency peaks).

Both earplug headphones reduced the lawn mower and metal saw noise to a degree that I felt protected, but ISOtunes were noticeably more effective than Plugfones.

Listening to music, podcasts, and audio books (Audible) worked with both of them, but not surprisingly, I had to play the Plugfones quite a bit louder.

Granted, for a different person, the Plugfones’ foam tips (NRR 29) might have been more competitive, but I didn’t get a good enough seal with these.

So for me, ISOtunes Wired win this noise reduction test.

Moreover, they come with four different sizes of foam ear tips (vs one for the Plugfones), giving the wearer a better chance to find a size that works for them.

extra small foam tips not shown

I am more into foam, but if you prefer to use triple-flange silicone ear tips in a high noise work environment, Plugfones are the way to go. ISOtunes do not offer silicone ear tips with a noise reduction rating.

Wearing earplug headphones underneath earmuffs (doubling up)

I also wore both underneath hearing protection earmuffs (NRR 24 and NRR 27).

Earmuffs somewhat change the shape of the ear canal, and for me this negatively affected the seal of the silicone ear tips. The foam ear tips worked much better in this double-protection scenario.

Plain foam earplugs though, because they have no stem, are still more comfortable when doubling up.

Everyday noise reduction

I tested both earphones against pink noise and coffee room chatter (60 dBA) and again the ISOtunes Wired were more effective than the Plugfones Guardian.

Playing a waterfall sound at a moderate volume as a masking sound, I was able to almost completely isolate myself from a noisy coffee shop.

Sound Quality

It is surprisingly difficult to compare the sound quality of these earphones.

As it turns out, the type (foam vs. silicone), size of ear tip, and insertion depth all heavily influence how they sound.

With both, I listened to rock, jazz, acoustic guitar, audio books and podcasts.

With the silicone tips, the Plugfones Guardian sound more balanced and more open than the ISOtunes with foam tips. They have good bass and mids and enough detail in the treble.

I tried the ISOtunes Wired with the mid- and the small-sized foam ear tips.

With the mid-sized tips (best seal for me) they have a bit too much bass for my taste and lack in treble, making them sound somewhat boomy and muffled.  They work fine with audio books.

Tip: I was able to reduce the bass with my phone’s built-in equalizer and then they sound OK, so that’s what I do. Amplifying frequencies didn’t work so well as that significantly reduced the overall volume. 

With the small-ear tips, the ISOtunes’ bass is more subdued and I get more treble. They sound a lot better now. They are still a bit veiled, but there is enough detail in the music for me to enjoy it.

I also tried them with the Guardians’ silicone tips (yes, you can screw them on) and then they sound more similar to the Plugfones.

Likewise, I also tried the Plugfones with the mid-size ISOtunes foam tips and then they too lose some of their clarity.

Overall though I prefer the sound signature of the Plugfones, so they win this round.

Notes: Expect OK sound, but if you don’t need high noise isolation, you should be able to find better-sounding similarly-priced earbuds.

Replacing ear tips and using third-party ear tips to improve noise reduction / sound quality

Replacing the ear tips

In particular with foam ear tips you have to expect to regularly change them (perhaps every month if you use them a lot on the job). You can wipe them with a damp piece of cloth but in the end they will deteriorate or become dirty.

Both ISOtunes and Plugfones offer replacement foam ear tips in sets of 5 pairs for purchase, so this shouldn’t be an issue.

In my experience, triple-flange silicone ear tips are more durable than foam and you can wash them with soap.

For the silicone tips, Plugfones offer replacement sets as well.

Using third-party ear tips

The nozzles of the ISOtunes Wired and the Plugfones Guardian have diameters (including the thread) of 3.6 mm and 4.3 mm respectively.


ISOtunes offer more sizes for foam tips and they seal well, so I thought these could potentially work with the Plugfones as well.

And indeed, the ISOtunes foam tips can be screwed on to the Guardian and work well; I would say the noise reduction is then in the same league. Perhaps due to their housing, ISOtunes still have a slight edge.

Obviously, if you need work earphones with a certified NRR, you have to use the ear tips provided by the manufacturer!

Still, if you prefer the Plugfones Guardian but the foam ear tips aren’t the right size for you, the ISOtunes Triology foam ear tips, which come in four sizes, are an alternative.

I also tried the Guardian’s silicone tips with the ISOtunes: this works as well and even improves the sound quality.

Note: changing the foam tips back and forth between the two earphones is not a good idea; if you put them on the Plugfones expect to use them there; the tips can otherwise become loose on the ISOtunes due to their smaller nozzle diameter.

Do they work underneath a motorcycle helmet?

I can wear both under my full-face helmet.

The housing of the Plugfones is smaller and disappears more in my ear, so I feel it less.

For use underneath a helmet, I would try Plugfones Guardian first.


Here is a size comparison with a standard 3M reusable silicone earplug to give you an additional reference. The stem of the Plugfones is quite a bit shorter:



Make sure that where you are planning to ride your bike, wearing noise isolating earphones is actually legal.

I understand that wind noise underneath a helmet can exceed 100 decibels, so folks want to protect their hearing. On the other hand, broadband noise reduction can potentially isolate you too much from your environment.

Also be aware that in particular the foam ear tips are very effective at reducing noise. If you then additionally listen to sound, you further increase your hearing threshold for outside noise.

Maximum volume

The ISOtunes Wired attempt to limit the maximum volume to 85 decibels (they call it SafeMax Technology) to keep you from playing your music at a volume that could damage your hearing.

The limiter worked well for what I was listening to. Because these earplug headphones isolate so well, I rarely had to max out the volume.

Plugfones Guardian don’t have a volume limiter. They offer a slightly more expensive version, the Protector VL that has the same housing and ear tips, but limits the volume to 82 decibels (they call it Worksafe).

Use with a Bluetooth receiver

These days, many phones don’t offer a headphone jack, but you can use an adapter (e.g., Lightning-to-3.5-mm or USB-C-to-3.5-mm).

I prefer to use an external Bluetooth adapter. This also gives me a microphone and volume and track control for a little extra money.

I tested both earphones with the Mpow BH129, a Bluetooth 5.0 receiver and they worked just fine.

That way you can even connect them to two devices at the same time.

Final Thought

I have stated my preference.

If you are not sure which ones to get, consider getting both earplug headphones.

This allows you to experiment with six different ear tips at a reasonable price and may prove useful if you later want to upgrade to one of their premium models.

As with all earplugs, getting a proper seal is paramount for effective noise reduction and hearing protection, and usually one size doesn’t fit all.

I hope this review has been useful. All the best.

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