Hi Roger
Why not do it yourself using Märklin mDecoderTool3 and its sound library
What you need:
- a PC or laptop with Internet access
- a CAT5 cable (internet cable (any kind will do: Normal or Crossover.
- download and install mDecoderTool3 using this link https://streaming.maerkl...oderTool3-v360-Setup.zip
- once you have installed and started the mDecoderTool3 version 3.6 and you PC is connected to Internet, download the Sound Library (SoundBibliothek) by selecting "Sound" tab and then "Sound Library" and then download


Now you need to import a BR 01 sound project
The Märklin sound projects are referenced by the loco article number. Sadly, there is no project for a BR01 in 1 gauge but multiple in HO gauge.
So here is a portion of 39xxx locomotives

If we want a BR01 sound we must select one of these
You may check the sound of each of them by doubleclicking on the loud speaker

When you like one sound project you checkmark if for download
When finished you have this screen

Now, you can map the fonctions and adapt the motor type (DC smooth normally)
- using either a CS3 or a DecoderProgrammer, program the loco or directly the decoder from a USB port of your computer.

So it looks like it is complicated the first time but it is part of the MRR fun
Cheers
Jean