I don't know if specific software exists for this. I myself would like to know if there is an easier way to do this.
But until someone tells me if such software exists, this is how you do it with Goldwave -the non registered trial version is enough-.
First thing: for this to work properly, you should verify original files that you recorded into Auria -or MultitrackDAW-. And only one file is enough to verify that all your recordings made by the interface are what they are supposed to be. 24bit. This means, export from Auria to Audioshare an original recording segment -or, from the BINS in MultitrackDAW, "open in" Audioshare-. Rename the file -in Audioshare- to something familiar so you can remember it. And then transfer it to a Windows computer.
So lets get to it. It is a slow process. But it is effective.
- *Download and install Goldwave -trial version is enough-.
*Open Goldwave and open the file you wish to verify.
*Go to the "Options Menu" and choose the "Window" option.
*In the "Axes Numbering" select "Signed 16bit (-32768 to +32767)" for "Y" and "Samples" for "X".
*Now, for simplicity sake, center the file in an area that is mostly silent.
*Use "SHIFT" "UP-DOWN Arrow" to zoom horizontally. And "CTRL" "UP-DOWN Arrow" to zoom vertically.
*To start of, zoom until the left of the file window has a range of "-12 to +12"; and until you can clearly see where the individual samples are matched to the left.
*If you are in an area of a file which is mainly quiet and you can clearly relate each sample values to the left, then now you can verify if it is 24 or 16 bit.
*If ALL the samples are matched to integer values on the left then your file is 16 bit even though Goldwave might say that it is 24bit.
*If, on the other hand, you can't tell exaclty what value your samples match to the left because they are between integer numbered lines, that means that they are not 16bit samples.
*For example: if the samples match to only integer numbers like 1, -6, -12, 4, 8, -3, 3, -12, 10... then the samples of your file are 16 bit.
*But, for example: if the samples match to something more close to: 1.2, -4, -5.3, 6.1, 8.5, -8.9, -4, 10.1, 12, -0.5... then the samples in your file are 24 bit.
Guitarjack 2, Line 6 Mobile In, Line 6 Sonic Port, Focusrite iTrack Solo, Focusrite Scarlett 2i2 and Rode iXY are some interfaces that I have tried and checked that provide true 24bit audio samples.
Tascam IM2, Tascam IM2X and Tascam IU2 don't deliver true 24bit. With these, you can see in Goldwave that even if the file says it is 24bit, the audio samples are 16bit.