need audible pulse out that varies "on time"

[mister_e]

So from what I feel, you'll need to use HPWM. Look in your datasheet to spot the CCP1, CCP2 pins, see if they're free, and If so, well, it's just a matter of few lines of code then.

Play around this one

if Strenght= 0 then
        HPWM Channel, DutyCycle, Frequency
        PAUSE 500
        CCP1CON = 0 ' turn of PWM
        LOW YourBuzzerOut (or high depending)
        PAUSE 500
        endif

if Strenght= 64 then
        HPWM Channel, DutyCycle, Frequency
        endif