Improve Taranis sounds for Vario

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Which board (stock / gruvin9x / sky9x / Taranis) are you using?
latest
What is your openTx FW version?
latest
What is your openTx EEPROM version?
latest
What steps will reproduce the problem?
1. Fly with vario sounds enabled
2.
3.

What is the expected output? What do you see instead?
I sometimes found it difficult to determine whether my plane has lift or is 
sinking. The sinking/lift tones are difficult to distinguish.

Multiplex has a great approach:

http://www.youtube.com/watch?v=1GO1XHhBxUE

They use normal "beeps" for rising, and "double-beeps" for sinking.
bib - bib - bib  =rise
blibib - blibib - blibib =sinking

I saw this live on my friend's radio, and liked it from the first second. It is 
much easier and clearer to know than the sounds on the Taranis.

Please provide any additional information below.

Original issue reported on code.google.com by extremf...@gmx.de on 16 Oct 2013 at 7:37

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OpenTx does it the same way as a full scale glider vario, so continuous tone 
for sink and intermittent one for lift. 

The biggest problem is not the sound, it's the low resolution of the vertical 
speed data from the FrSky vario. It only reports vertical speed in increments 
of 0.5m/s, and it's really a bit too coarse as it in a slow descent instead of 
reporting -0.3 or so it will continuously switch between -0.5 and 0...

Original comment by bernet.a...@gmail.com on 19 Oct 2013 at 12:37

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Hello Bernet,
the Vario tone of Taranis goes from min. 640Hz over 1000Hz at 0m/s to max. 
2000Hz. Correct? It sounds good.
However, the Vario pilots from the great sailplanes love a lower frequency 
location.
So at 0m/s approx 300Hz down to 10Hz at -4m/s sinkrate.
I know, the lowest steps are limited by the timer. Often only a coarser 
gradation of frequency is possible. I think this is no problem at the low end.
What do you think about my proposal.

An other point:
Particularity of the three different variometer sound schemes
It is very important for the pilot to know in which of these three areas he 
actually is. In order to distinguish these three areas three different tone 
schemes have been set up. The zero lift area is particularly valuable.

The sinking below the sinking threshold is indicated as usual with a continuous 
tone the frequency of which becomes lower at increasing sink rate. Climbing is 
always indicated with an intermittent tone the frequency and pulse rate of 
which increases with increasing climb rate.
In the zero lift area you will hear no tone.
This way real climbing, start of climbing within the zero lift area as well as 
sinking can easily be distinguished one from another.
This particularity has been adopted from wsTech variometers by some tramsmitter 
firwares.
Nonetheless the thresholds are configurable per model by the user in the vario 
menu.

Best regards,
Wolfgang  

Original comment by wsh...@gmail.com on 4 Jan 2014 at 6:35