The original version BeepFX 1.11 which is
"Beeper sound effects cross editor for ZX Spectrum 48K. Generates sound effects using small set of parameters, also has sample support. Source code included."
available at http://shiru.untergrund.net/software.shtml.
Original version is limited to ZX Spectrum users only however audio effects produced using just 1bit sound can be used in modern games also. The problem is it doesn't saves audio in wav etc format. For the same i edited the source and added Export RAW & WAV formats in batch. Editing source was not easy because i couldn't install Borland Studio 2006 on both Windows and Linux. So had to install VirtualBox with windowsXP and worked inside it. The source along with the BeepFX 1.12 binary is available below link -
There is also online version of similar software capable of producing nice audio effects.