I have an iMac, the USB connection Companion 5
1 - When I click on an mp3 file open Audacity, audacity opens normally, my soundtrack is, I start playing, no sound output.
2 - I normally opens audacity, audio import,
The soundtrack opens normally, I start playing, I hear the sound.
A bug ???
I moved this from the French forum given you wrote in English.
Please look at the pink panel at the top of the page. What version of Audacity? What version of OS X? If you have Yosemite, Audacity 2.0.6 does not officially support it.
Are you importing the same file in 1 and 2?
If after doing 2, you do 1 again, is there still no sound?
Is there always sound if you reboot the computer?