test-speech: 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 CentOS possible default full paths are:

/usr/bin/test-speech - from package: gnome-speech

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/test-speech - from package: libgnome-speech-dev

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

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