raw2wav: 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/raw2wav - from package: vpb-utils

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

Error in other languages:
raw2wav: bevel nie gevind nie
raw2wav: comandă negăsită
raw2wav: comando não encontrado
raw2wav: commande introuvable
raw2wav: command not found
raw2wav: käsku ei ole
raw2wav: không tìm thấy lệnh
raw2wav: komanda nerasta
raw2wav: Kommando nicht gefunden.
raw2wav: kommandot finns inte
raw2wav: komut yok
raw2wav: nie znaleziono polecenia
raw2wav: níor aimsíodh an t-ordú
raw2wav: no se encontró la orden
raw2wav: no s'ha trobat l'ordre
raw2wav: opdracht niet gevonden
raw2wav: parancs nem található
raw2wav: perintah tidak ditemukan
raw2wav: príkaz nenájdený
raw2wav: příkaz nenalezen
raw2wav: команда не найдена
raw2wav: командата не е открита
raw2wav: 命令找不到
raw2wav: コマンドが見つかりません