whau.wav: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/share/games/oneisenough/bin/sounds/whau.wav - from package: oneisenough

You may install the required package with command apt-get install {package}

Error in other languages:
whau.wav: bevel nie gevind nie
whau.wav: comandă negăsită
whau.wav: comando não encontrado
whau.wav: commande introuvable
whau.wav: command not found
whau.wav: käsku ei ole
whau.wav: không tìm thấy lệnh
whau.wav: komanda nerasta
whau.wav: Kommando nicht gefunden.
whau.wav: kommandot finns inte
whau.wav: komut yok
whau.wav: nie znaleziono polecenia
whau.wav: níor aimsíodh an t-ordú
whau.wav: no se encontró la orden
whau.wav: no s'ha trobat l'ordre
whau.wav: opdracht niet gevonden
whau.wav: parancs nem található
whau.wav: perintah tidak ditemukan
whau.wav: príkaz nenájdený
whau.wav: příkaz nenalezen
whau.wav: команда не найдена
whau.wav: командата не е открита
whau.wav: 命令找不到
whau.wav: コマンドが見つかりません