How to generate sound effects without using musical ICs like UM66

[Rohit]

Is there any way by which i can generate sound effects generated by
musical ics like UM66 and many other similiar ICs. I want to generate
police siren, Jingle bell and happy birthday sounds. Can these sounds
be generated by PWM? I read that these ICs have ROM in which sound
notes are preloaded. But Do these notes mean generate a particular
frequency signal.
If anybody can explain the mechanism by which these sounds can be
generated, it'll be helpful. i intend to use a microcontroller with
onchip ROM so I can store these notes only if I know how to use them
and what they actually generate.

 

[terryc]

Is there any way by which i can generate sound effects generated by
musical ics like UM66 and many other similiar ICs. I want to generate
police siren, Jingle bell and happy birthday sounds.

Not sure about every particular tune, but in the past, circuits existed
from transistors that generated various sirens, etc. The devil in in the
detil as to which siren you want to make.

 

[LVMarc]

Is there any way by which i can generate sound effects generated by
musical ics like UM66 and many other similiar ICs. I want to generate
police siren, Jingle bell and happy birthday sounds. Can these sounds
be generated by PWM? I read that these ICs have ROM in which sound
notes are preloaded. But Do these notes mean generate a particular
frequency signal.
If anybody can explain the mechanism by which these sounds can be
generated, it'll be helpful. i intend to use a microcontroller with
onchip ROM so I can store these notes only if I know how to use them
and what they actually generate.

Learn to play an insrument, and record that :-0
Marc

 

[MooseFET]

At the other end of the extreme, with a lot of processing you could
output sound that would, in theory, be high fidelity (44.1kHz sample
rate, well over 10 bits at the highest frequency, much better than that
at the low frequency) at the cost of requiring a fairly healthy DSP chip
with a fancy PWM driver (something like a TMS320F28xx).  At this point
your system cost would probably be more than just using a hi-fi CODEC,
but it could be done without if you really wanted.

Even a part like the F120 from Silabs can do fairly impressive sound
on its DAC outputs. The DAC can be programed to update on a timer
overflow so that the processing time doesn't change the phase. You
can make the sound effects a lot "fatter" by modulating the reload
number for the counter to FM the output slightly.