Originally Posted by Heinrich S
In your experience what is the lowest amount of any type of distortion that a person can hear before it becomes inaudible while listening to music? -70 dB? -100 dB?
Based on DBTs - about -60 dB. That is a more global number. The instantaneous dynamic range of the human ear is about 60 dB under ideal conditions. If something pure is playing at 0 dB, then anything that is 60 dB or more down is highly unlikely to be heard.
Do you have appropriate test signals I can use for testing purposes? Do I add in a music track and then tell the program to add in distortion to amounts I deem acceptable for hearing, or is the actual test signal a music file that has distortion recorded in it?
For ABXing you need two files - the original music and the orgional music with the distortion added. If you are interested in studying thresholds, then you need a number of files with different amounts of distortion added.
I would be a great exercise to be able to see what is and isn't audible.
This is a link to a Dropbox account that contains a bunch of files that you can listen to and do your own comparisons:
There are 19 very brief files of piano music.
piano_nlref.wav - is the reference music file. Compare all the rest of the files to this one. It is as recorded from a very clean high bandwidth source.
The 18 other files are named as follows:
is the name of the family of files2nd
is the order of distortion10pct
is the percentage of distortion that was added.
I recommend starting with the highest order of distortion and largest amount of distortion and working down. IOW start with 5th order distortion and 30 percent and first work down the percentage of distortion, and then select the next lowest order of distortion. Repeat.
Each file is about 1 megabyte.
I do not guarantee that these files will remain available indefinately, so grab them while you can! ;-)
Also: Ethan Winer's files of a similar nature: