I want to make a sound generator for a radio controlled model.  The model
already has a few
PICs on board for feedback control of motors and a few other tasks, so I was
planning to
use one of them for sound generation (deisel engine sound keyed to
throttle).

I looked at some of the Holtek sound chips, but they are not EPROM or even
OTP.  All
waveforms have to be masked on the ROM, and I don't want to pay for a run of
10,000
chips when I only need one.

My scheme for using a PIC is to repetitiously play a waveform into an 8-bit
DAC.  My stored
data would be about 30 data sets of frequency, duration and volume to define
an approximated waveform.  The frequency would define the delay between DAC
updates.  The
duration would be how many cycles to play the current frequency.  Volume
or -volume would be the value plugged into the DAC at each switch event.
The DAC I am considering is a
MAX5018.

The duration would be further scaled to indicate engine throttle setting at
any given moment.

Is there a better way to do this, or a better DAC to use for this
application?