I need to produce a sound but not a simple tone in 8051 with moving coil speaker.

Hardware: connecting with 270ohm, 10uF, and P1.7 in 8051 seriously with moving coil speaker.


Software:
it can't use timer 2 auto mode because it is 16 bit thing... therefore i've used timer 0 mode 1 to try to produce a sound.

;This program demonstrates using the on chip programmable timer approach to
;generate the ambulance siren on the speaker.


$TITLE(Sound Effect of Laser Gun - Timer Approach)
$DATE(28-Dec-00)
$LIST
$MOD51
;Symbol and Data Section
TEMP_LO DATA 30h ;Temporary location for holding the initial
TEMP_HI DATA 31h ;value - low and high bytes respectively
LOOP_COUNTER DATA 32h ;Loop counter for laser gun

ORG 0000h

LASER_GUN:
MOV TMOD,#01h

GUN_1: MOV LOOP_COUNTER,#60 ;Initialize the LOOP_COUNTER
MOV TEMP_LO,#55h ;Loading the default initialize
MOV TEMP_HI,#0FFh ;value for timer 0 of freq 2700 Hz

GUN_2: MOV TL0,TEMP_LO ;Get low and high byte initial value
MOV TH0,TEMP_HI ;to timer register TL0 and TH0
SETB TR0 ;Start timer 0
MOV R5,#3 ;Set delay for 6 ms
ACALL DELAY
ACALL UPDATE
DJNZ LOOP_COUNTER,GUN_2
CLR TR0 ;Stop timer 0
MOV R5,#250 ;Set delay for 0.5 sec
ACALL DELAY ;Total delay = 1 sec
SJMP GUN_1

HERE: JBC TF0, GUN_2
SJMP HERE

;Update the initial value to be loaded to the timer 0
UPDATE: CLR TR0 ;Stop timer 0
CLR C
MOV A,TEMP_LO
SUBB A,#1
MOV TEMP_LO,A
MOV A,TEMP_HI
SUBB A,#00
MOV TEMP_HI,A
RET
;Time delay for [(12 + 12*5 + 24*200*5 + 24*5 + 24)*R5 + 24] clock cycles
;i.e. approx. R5*0.002 sec
DELAY: MOV R6,#5 ;12*R5 clock cycles
DEL_1: MOV R7,#200 ;12*5*R5 clock cycles
DEL_2: DJNZ R7,DEL_2 ;24*200*5*R5 clock cycles
DJNZ R6,DEL_1 ;24*5*R5 clock cycles
DJNZ R5,DELAY ;24*R5 clock cycles
RET ;24 clock cycle
END

I don't know why It still can't produce any sound out!
PLease help! or can somebody give me other ways to write the programme? Thank you!

P.S. i think the hardware is not the problem but the problem is from the program.