Each file is 0.1 s of a 440 Hz sine at ffmpeg's default amplitude of 1/8, made with its sine source, with metadata stripped and -bitexact so that the files do not change from one ffmpeg build to the next. Stereo files are the mono tone upmixed by -ac 2, which puts 1/√2 of it in each channel.

g() { src=$1; shift; ffmpeg -hide_banner -loglevel error -y -f lavfi -i "$src" -map_metadata -1 -bitexact "$@"; }
g "sine=frequency=440:sample_rate=44100:duration=0.1" -c:a pcm_s16le tone-s16-mono-44100.wav
g "sine=frequency=440:sample_rate=22050:duration=0.1" -ac 2 -c:a pcm_f32le tone-f32-stereo-22050.wav
g "sine=frequency=440:sample_rate=8000:duration=0.1" -c:a pcm_u8 tone-u8-mono-8000.wav
g "sine=frequency=440:sample_rate=48000:duration=0.1" -ac 2 -c:a pcm_s24le tone-s24-stereo-48000.wav
g "sine=frequency=440:sample_rate=44100:duration=0.1" -ac 2 -c:a flac tone-stereo-44100.flac
g "sine=frequency=440:sample_rate=44100:duration=0.1" -c:a flac -f ogg tone-mono-44100.oga
g "sine=frequency=440:sample_rate=48000:duration=0.1" -c:a libopus -b:a 32k tone-mono.opus
g "sine=frequency=440:sample_rate=48000:duration=0.1" -ac 2 -c:a libopus -b:a 64k tone-stereo.opus
g "sine=frequency=440:sample_rate=44100:duration=0.1" -c:a libmp3lame -b:a 64k -id3v2_version 0 -write_xing 0 tone-mono-44100.mp3
g "sine=frequency=440:sample_rate=44100:duration=0.1" -c:a libmp3lame -b:a 64k -id3v2_version 0 tone-mono-44100-lame.mp3