Bests & Worsts Reviews from Amazon

As an audio engineer and prior member of the AES (Audio Engineering Society) I'd like to offer the following comments Most reviews are very confused about this "Digital Sound Noise Meter". I also should note that many of the reviewers were supplied with free samples! I'M not sure exactly what a "Digital Sound Noise Meter" is but I'll assume that it measures db SPL, aka sound pressure levels, using the db scale. Without knowing the frequency response of the microphone, it is largely a useless device. One reviewer, in a video, says it is 300hz to 8,000 hz without specifying deviation. That's close to the range of a telephone. (Human hearing goes from 20hz to 20,000hz). Other reviewers state the manufacturer specifies it is plus or minus 2db at 1000hz at 94db SPL. To understand exactly how meaningless that spec is consider the meter claims a range of 40 to 130 db SPL yet it is only tested at 94 db SPL. Secondly human hearing, as noted, runs from 20 hz to 20,000 hz/ Most meters would cover maybe 130 hz to perhaps 8,000 hz. Finally, the manufacturer self certifies these meaningless specs and no independent lab confirms them which would be the norm with quality meters. I have no doubt the numbers on its display increase in some manner as the sound gets louder. So what! It takes a fair amount of money to manufacture a good microphone. It takes even more money to calibrate it so it accurately displays db SPL. I doubt, in a hundred years, you could manufacture an accurate microphone for $20.00 But lets assume you have a quality meter. You still have to know how to use it!! Typical misconceptions: Distance from the sound source REALLY matters. Place your cell phone (using speakerphone) and this meter next to each other and you'll see a fairly high db SPL level. Move the meter 6 inches away and the db SPL will drop considerably. Move the "meter" a foot away and it will drop considerably more. I'm not sure what this device is beyond a microphone of dubious quality that vaguely increases its reading as a sound gets louder. That may or may not relate to true sound pressure levels. What is clear is that some top notch reviewers don't know what they are reviewing. For example: place this "meter" very close to a loudspeaker and you will then get a very high db SPL level as one video reviewer did. You could then incorrectly pronouce that speaker as damaging to human hearing. That is almost certainly the wrong conclusion. This shows a fundamental misunderstanding of how distance effects sound pressure levels. Another easy test: speak with any friend in some typical setting. Now move closer, without your friend changing their volume or tone. Put your ear next to your friends mouth (if you dare and I don't advise this) and you will see how distance effects volume (aka db - SPL) I'm afraid there are a number of very flawed reviews that have little understanding of this type of product or how to use it. The seller has capitalized on many well intended yet very flawed reviews by highly rated reviewers to promote sales. Many reviewers were provided with free samples. Within a day of when I posted this review I received a YES "Was this review helpful to you?" Yet the next day two negative votes came in. These negative voters left no comments. I wonder who posted those votes. I have my suspicions