The unit produces namely permant, even coupled a whirring sound at high frequency. This is regardless of whether and where it is installed, but always occurs.
In a room where there is always a certain amount of noise, which is certainly not a problem. Mir whimpers but it unbearable in the ear.
Otherwise, both mounting and coupling of different devices such as PC or iPhone were uncomplicated.
So the idea is good, but the execution poor.
Very sad, especially for the price - actually already outrageously. In my opinion, since should indicate in the product description, it is not suitable for all applications!