aumix: 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/bin/aumix - from package: aumix-gtk
/usr/bin/aumix - from package: aumix

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

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