speakup_setlocale: command not found

Have You tried accessing the binary with the full path?

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/speakup_setlocale - from package: speakup-tools

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