after a long time of reflection and a good night sleep ,I came back to edit my answer.

short answer beep will not work under android since android doesn't have an internal system speaker and no kernel module pcspkr , I tried to beep old school way with the command `echo -en "\a" > /dev/tty5` but it will not work since android doesn't have an internal speaker.

But nothing is impossible you can make your own beep program easily following this steps :

 1. make sure you have the binary `aplay` on your phone have it under `/system/bin` it is used by the system to play boot sounds if you don't have it grab the arm version from [here][1] and put it under `/system/bin` on your phone and give it the right permission it have to be executable.
 2. download this beep.wav file from [here][2] and put it somewhere on the system partition of the phone or any where else your choice in my exemple it will be `/system/beep.wav`.
 3. now you can either beep usin this command 

    aplay /system/beep.wav

or you can make a script file name it beep and put it under `/system/xbin` or `/system/bin` you can either over right or rename the old copy since it is just a simlink or the busybox binary you can always call the original beep by `busybox beep` command and don't forget to give it the execute permission .
here is the simple exemple of the script you write 

    #!/system/bin/sh
    aplay /system/beep.wav


this will beep your device with the current default speaker it can be the phone's speaker ,headset or Bluetooth headset ,you can change that using the aplay option `-Dnameofpcmdevice`  

this script can only beep once but ,I see many possibilities can be added easily ,like playing other sounds alarm and adding arguments like frequency..ect


externel links reference and assets :

http://linux.die.net/man/1/beep

http://www.soundjay.com/beep-sounds-1.html

http://media.io/ >> great online service to convert sounds to wav format supported by aplay

I hope this will solve your problem or at least give you an alternative 

  [1]: https://www.dropbox.com/s/om6xrwfgb8h3vqa/aplay?dl=0
  [2]: https://www.dropbox.com/s/monpiypo9800jb9/beep.wav.zip?dl=0