Why? Simply you might import and work on a MP3, but you don’t know which type it is. Further more, when you want to save your work, you need to know which options you want to set for, normally no point in exporting in 192Kps if your input is in 64bits!
Secondly,
the possiblity to display measurement time in in 1/10 sec. Usualy, hh:mm:ss is not sufficiently accurate and hh;mm:ss mmmm is acurate, but not easy to read.
Once an audio file has been imported into Audacity it is not an mp3. Audacity uncompresses the file so that it can be processed.
The “Project Rate” is not a reference to the original file but to the default sample rate that is used in the current project. All files, no matter which will be played at the project rate, and exported at that rate. Should the sample rate of a track be different from the Project Rate, these tracks will be resampled to the Project Rate as the project is played back or exported.
The project rate can be changed by clicking on that number and selecting another from the drop-down menu.
Since Audacity supports multiple tracks, and the tracks may include samples from different sources, it is more meaningful to display the project rate than the original format of the source file. You can find the properties of the source file by right clicking on the file and selecting “Properties > Summary”
