audio_rename: 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/audio_rename - from package: libmp3-tag-perl

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

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