We all know that hearing aid is normally use by the deaf people, who cannot hear properly, but It happens due to an internal process of the hearing aids that technically works by an mechanism which collect the signals from the outside.
The process is known as hearing induction loop. In this process, a magnetic wireless signal picked by the hearing aid and it will directly convert it into a audio signal and transfer to the user ears, so he/she can hear the voice and it will not collect the unwanted voice.
It is available in affordable price so user can buy it. Like this another object will be use to mix the audio known as mixing consoles. It will convert or the volume level or tone in another form. It is specially used in microphones which are used by the singers. You can get more information about it on the internet.
To get more details, visit at http://www.jands.com.au/
Source : http://jandsproducts.blogspot.com/2017/06/convert-you-voice-with-help-of-mixing-consoles.html