Crontab starting audio player

I need to run an audio file from a cron job. This works in a crontab:

1,5 * * * * play /home/username/bin/audio.wav

Problem is that if another program such as Totem or VLC is using the sound card then it won't play.

As a work around I have been trying to get VLC or Totem to play the files instead as they don't mind being interrupted or playing over the top of each other. This works on the command line:

totem /home/username/bin/audio.wav

or

vlc /home/username/bin/audio.wav

However when you put them in a crontab they fail to execute, ie any of the following:

1,5 * * * * totem /home/username/bin/audio.wav
1,5 * * * * /usr/bin/totem /home/username/bin/audio.wav
1,5 * * * * vlc /home/username/bin/audio.wav
1,5 * * * * /usr/bin/vlc /home/username/bin/audio.wav

I don't have access to email messages sent form the crontab but accessing the logs using this:

cat /var/log/syslog | grep -i cron

Shows the cron run with nothing that looks like an error

Ideas?