resynth: 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/resynth - from package: speech-tools

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

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