ebook-speaker: 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/ebook-speaker - from package: ebook-speaker

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

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