Talkback on an existing switch

Talkback is a function that can be added to the radio. Talkback enables the radio operator to hear his/her voice through the radio's internal speaker or an external speaker. This Talkback feature is set at a fixed volume level and is then tied to an existing switch on the radio so that the operator may turn the Talkback on and off when desired. Normally either the CB/PA or CH9 switches are used in this application. Talkback is imperative if you intend to add a noise toy or echo. It enables the user to hear when the toy has finished, and also aids in setting an echo.
The acoustics of every auto varies from one auto to another. External speakers have a different tone and loudness characteristics from one brand and model to another. The sensitivity of one brand of mic compared to another is also quite different. We need to know what type of mic, the brand and model of speaker to be used and approximate placement of the speaker in relation to the mic in order to set the loudness of the talkback.

Please indicate the desired switch to use and how you would like the factory's function set.
For Example: Use the BRT/DIM switch. Set the lights to bright. Notes may be added to the note section when placing the order.