This is a set of WAV files at various audio frequencies, for testing of audio equipment. They are written in 16-bit 44100Hz format, and are constant-amplitude. Recall that constant-amplitude means the acoustic power increases with higher frequencies, so use very low volume levels to avoid ear injury. The MATLAB script used to generate the files can be downloaded here.
For uncompressed audio, the sample rate and bit depth determine the sound quality as well as file size. Unfortunately there are many comparisons online which misrepresent the true effect of changing sample rate and bit depth, because compression is applied either at the source or after down-sampling, which makes the audio sound even worse. I took a 30-second sample from the song Photosynthesis by Carbon Based Lifeforms, downloaded in lossless FLAC format, originally at 44100 sa/s and 32 bits/sa. Then I down-sampled this to 22050 sa/s and 11025 sa/s, as well as 16 bits/sa and 8 bits/sa, using audacity and a scilab script. The resulting files are saved in lossless WAV format and can be downloaded below.