modify below function
Global settings->Text to speech/Sounds->Distance for TTS
Not a fixed distance for 1/2/5/10/20/50/100/1000(Km)
can select meter/kilometer and key-in any numbers
when hiking this function is more help to know km Distance below the mountain topo,
for example every 50/100/200/~900m Message to speech:Time/Altitude/Distance......