Not for Vocal Clarity
938681
Just purchased this based on previous reviews and after 1 hour of using it, I'm returning it.  As a vocal coach I purchased it to have a wireless mic for mobility in my classroom.  The sound quality is terrible, not clear and "scratchy".  I only gave it one star because it seems sturdy and compact if you wanted to use it for other purpose...not one of which I can think of at the moment.
4608225
Bought this as a possible solution for recording loud concerts based on the review here.

The built in microphones on smartphones are engineered towards normal speaking voice noise levels.  When you try to use your built in smartphone microphone to record louder sounds (like live music), the result is usually a recording plagued by horrendous levels of distortion (please see the multitudes of live concert smartphone recordings over at youtube for examples).

This microphone seems to be geared towards providing a HOTTER signal than a smartphone's built in mic.  In other words, it makes the distortion problem worse.  Even with the highest level of gain reduction on my recording app, levels still went far into the red.  To be very fair, the product description strongly hints at this by saying it is more sensitive.

I tested the Monoprice mic, the built in mic on my Moto G and a home-built version of the Bootlegmic, recording the same section of music at live music levels, 2 feet away from the speakers.  The Bootlegmic faired best (with -14db gain reduction), followed by the built in smartphone mic (which distorted even when not showing overload in the app).  The Monoprice mic came in last.  It just wasn't possible to reduce gain on the mic (my app maxes out at -20db) enough to keep it from overloading.

So, if your goal is to record loud live music or sounds, this mic is not for you.  However, if you are looking for GREATER sensitivity to record conversations, meetings, field recordings - you can't go wrong with this mic.  It is well constructed and has pretty good frequency response.
3306770
Very disappointed.  While the outgoing voice is recieved clear on the other end, the incoming voices sound distant, and are muffled.
4949394
I'm really quite bummed about this because I wanted it to work badly. Setup was easy and the voice prompts to answer, etc were neat. Also what was cool was the access remotely to your address book via voice commands. My problem is the sound quality. It seemed as though people could hear me well enough, but I could not hear them through the built in speaker. Once I turned up the volume load enough to hear them it was an offensive amount of distortion through the speaker. I tried using the FM function to forward audio to my cars speakers but in Chicago it just didn't work well at all. Also I travel extensively so the prospect of switching the FM stations to find clarity is just ridiculous. I do drive a mini van that is 8 years old and has a lot of road noise at 75mph on the highway, more then most cars I'd say. So maybe if you drive a whisper quiet Lexus etc, the internal speaker might not need to be maxed out like in my car. I will have to keep looking.
4440404
I returned this Headphone because I wanted a clear and stereo surround sound to listen to my daily meditations but the sound had a constant hissing in the background and an annoying scratchy noise every time I moved my head. Those sounds made it impossible for me to concentrate and focus on my meditation. I was very disappointed!
2163634
This a solide good quality product with more amps than others on the market. It recommended to me by Amazon. My voice is very weak and I thought is gonne help me to amplify my voice so my wife could hear me from the next room ...
Unfortunately the mic is not as good as the base ( speaker) because when I turned the volume louder towards maximum I can hear lots of annoying pops in the speaker which are covering the words
My wife can not understand the words because the pops are unpleasantly loud ...
I returned it because I could not use it. It did not serve my voice. I would suggest the manufacturer to produce a better mic to eliminate the pops ...
2561980
Felicia (the singer on this cd) sounds lovely and all, but I expected her to be asian when I heard this album.  Her voice sounds compressed and forcibly so.  Especially in track 1 Exordium: A Legend Foretold.  This woman can sound deep and sensual, as you can hear in track 3, but continues to sheepishly constrict her voice to sound tiny and annoying.  Its a shame, cause the lyrics and music are so enticing.

Felicia does a lot of christian music as well.  I guess this fits in well with restraining herself in more than her singing.  I still listen to it since it provides a nice detour from Enya and the likes.  However a european based album better have a strong european woman's voice on it when she chants and sings, not one who tries ever so hard to  beat her own voice down to sound meek.
2543227
The recorded sound from these are very muffled, lacking definition and clarity. I guess other reviewers might have very low standards, but don't expect much from this. My cheap mic provides much clear sound. It does have it's uses though.. it kind of has an old-fashioned warm sound to it that might be useful if you're looking to add that kind of sound to your recording. That's the only benefit I can think of.
4670124
Seems to do a reasonable job of capturing sound and is easy to use. But the loud hiss you hear in the quieter parts of your recording make it unusable for any serious music, which is what I wanted it for.
2447664
Unless you really turn up the volume, the hiss on these headphones is intolerable. Using them for a conference call/web conference is almost useless. Hiss overwhelms voices. Really disappointed for the price. I've tried turning up the volume to the level at which the hiss goes away, and the sound is so loud it must be damaging. I hope i can send these back.
1350764
Nice quality, but do not cancel noise as I expected.
Returned.
3032983
These headphones are great for talking but not for listening to music. Music sounds awfully high pitched even when attempting to use an EQ to normalize.
1723681
Signal-to-noise ratio is low. There's also a "pumping" compression when the source signal drops below a certain threshold. Very annoying when listening to material with high dynamic range, like movies. Because of this, I barely use the device. Would not purchase again.
1073436
When using this microphone people said they could not hear clearly.
2456857
I have heard better clarity especially of "I can help" his biggest song . This is a budget line cd but anyone listening to it won't become a fan due to the lack lustre audio quality. It could be much better. The equalisation is not right.
1877378
You have to practically swallow the small microphone to make it work.  Yes if I had a mask it would work okay but just was not what I was looking for.  It does make your voice sound deeper or higher.
3045053
pick up a lot of the surround sound,  clients complain about the sound of my voice being too low unless I put my mouth near the mouthpiece which would be ok if the microphone was longer or more flexible.  I would not recommend to anybody who does telemarketing