[lcrs]

Similar results - converting to a square image at 8bit then lowering JPEG quality just gets noisy in an uninteresting way:

    sox mo.wav -e unsigned -b 8 -c 1 -r 48k mo.raw
    bytes=`stat -f %z mo.raw`
    width=`echo sqrt\($bytes\) | bc`
    square_bytes=`echo $width \* $width | bc`
    dd if=mo.raw of=mo_square.raw bs=$square_bytes count=1
    gm convert -depth 8 -size ${width}x${width} gray:mo_square.raw -quality 50 mo_square.jpg
    gm convert mo_square.jpg gray:mo_square_jpg.raw
    sox -e unsigned -b 8 -c 1 -r 48k -t raw mo_square_jpg.raw mo_jpg.wav