Hi Momen,
I haven’t tried them personally as I am already hard of hearing. However, this style of ear insert will alter the diameter of your ear canal. The ear canal naturally resonates at 4kHz (i.e. it naturally amplifies high pitch sounds that are critical in certain speech sounds).
Calmer manufacturers (Flare Audio) claim this is “distortion”, however it is absolutely not distortion.
In English language, for instance, speech has evolved so that sounds at the 4kHz point are spoken very quietly. If you say “Eh for everyone” then “Fff for foxtrot” at a normal speaking volume, you’ll notice that the 4kHz “F” sound requires much less speech effort from your throat than a vowel sound like “E” (pronounced Eh).
If you take away the ability of the ear canal to enhance/amplify/resonate at 4kHz, you effectively give yourself a high frequency hearing loss. I wrote to the Calmer/Flare team on Facebook to raise my concern about this, and they told me that the earplugs do not lower hearing ability enough to cause a problem.
While I am pleased they have actually thought about it, I am not sure they can say they have research showing everyone’s responses, every individual‘s possible outcome.
The link between hearing loss and cognitive decline (among other things) is beginning to be understood. Someone with Noise Induced Hearing Loss (NIHL) would have a poor hearing threshold at mainly 4kHz, and they would struggle to perceive speech if it was in background noise. 4kHz is critical.
Psychologists are studying misophonia (strong, negative, emotional responses to sounds). Audiologists are studying hyperacusis (intolerance of louder, typically high frequency sounds). I have yet to see any research / fact-based advice recommending you reduce sound input. I only know bad things about what happens when you reduce sound input to the brain. Things like a long-term inability to process speech, rerouting of auditory neural resources, effects on cognitive processing, dementia, depression - the list goes on!
With any phobia or psychological intolerance, the cure is to safely challenge it and overcome it. In the case of a fear of heights, you can effectively avoid them for life. In the case of 4kHz and other high pitch sound frequencies, you literally need them all day every day to communicate. They are everywhere. I have huge concerns about promoting long term sound blocking /manipulation as the answer to an issue that a good therapist might be able to work through with you.
At the very least, Calmer needs to be promoted honestly and with caution. It is not removing distortion. Calmer’s own technical data shows that they in fact distort the natural reception of sounds that are critical to humans' speech reception. I have not seen test data from human subjects using sound probes, only averages/models with average ear canal capacity on the Calmer website. I do not see how this can prove an individual will not get a noticeable threshold shift that may cause processing issues for them.
The same applies to noise cancelling headphones and any form of ear protection. Protection from overly loud sounds is fantastic. “Protection” from speech level sounds is not.
Reduced sound reception can cause tinnitus, cognitive decline, auditory processing problems, and is even linked to dementia.
Bottom line: If they are worn daily, they will simulate high-frequency hearing loss. They cannot help you come to terms with sound, they can only put a sticking plaster over the issue.
Please note that these are my opinions and concerns as an audiologist. As a human being, I understand that misophonia can be crippling and help can be difficult to obtain. I am not saying the cost is not worth the benefit, I am simply saying that we should be aware that there may be a cost to continually distorting sound input. Apart from tinnitus (which can be generated quite quickly) the other issues I raise are from long-term exposure to hearing loss.
I am not saying that wearing earplugs for 5 minutes a week will cause dementia, but I would advise limiting use as much as possible, and avoiding use in young children who are developing speech and language ability, which relies on accurate reception of speech in order to copy and produce the sounds themselves.