sendpraat: 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/sendpraat - from package: praat

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

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