FFmpeg silent audio, broken video

Last login: Mon Jun 19 15:43:23 on ttys001
peters-macbook-pro:~ peter$ cd Desktop
peters-macbook-pro:Desktop peter$ ./ffmpeg -f concat -safe 0 -i <(printf "file '/Users/peter/Desktop/WordHeadingsWo.mp4'\nfile '/Users/peter/Desktop/WordClipsWo.mp4'\n") -c copy "WordsWoFailedLatestVersion.mp4"
ffmpeg version N-86499-g1edbf5e-tessus Copyright (c) 2000-2017 the FFmpeg developers
  built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
  configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzmq --enable-libzvbi --enable-version3 --disable-ffplay --disable-indev=qtkit
  libavutil      55. 66.100 / 55. 66.100
  libavcodec     57. 99.100 / 57. 99.100
  libavformat    57. 73.100 / 57. 73.100
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 92.100 /  6. 92.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f9e79013600] Auto-inserting h264_mp4toannexb bitstream filter
Input #0, concat, from '/dev/fd/63':
  Duration: N/A, start: -0.021333, bitrate: 140 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1280x934 [SAR 1:1 DAR 640:467], 68 kb/s, 24 fps, 24 tbr, 12288 tbn, 48 tbc
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 71 kb/s
    Metadata:
      handler_name    : SoundHandler
Output #0, mp4, to 'WordsWoFailedLatestVersion.mp4':
  Metadata:
    encoder         : Lavf57.73.100
    Stream #0:0(und): Video: h264 (Constrained Baseline) ([33][0][0][0] / 0x0021), yuv420p, 1280x934 [SAR 1:1 DAR 640:467], q=2-31, 68 kb/s, 24 fps, 24 tbr, 12288 tbn, 12288 tbc
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, mono, fltp, 71 kb/s
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f9e7901b200] Auto-inserting h264_mp4toannexb bitstream filter
[mp4 @ 0x7f9e7902d000] Non-monotonous DTS in output stream 0:0; previous: 48902, current: 48796; changing to 48903. This may result in incorrect timestamps in the output file.
frame=22747 fps=6229 q=-1.0 Lsize=  162257kB time=00:15:56.85 bitrate=1389.1kbits/s speed= 262x
video:146752kB audio:14994kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.316634%
peters-macbook-pro:Desktop peter$