Your speaker is the recommended ohm value, according to the datasheet.
It ought to work. The APR9600 is supposed to put out 1V to a speaker. 12.2 mW. It won't be loud, but it should be audible.
Questions:
* Is your power supply within the range between 4.5 V (minimum) and 6.5 (maximum)?
* Can you be sure the device has a recorded audio message for it to playback? Or else does it produce beeps, etc.? Anything so you can be sure it is playing back some sound.
* Can you hook up an AC voltmeter to the output pins when playing back? Does it show a reading?
* Can you hook up a different speaker, or headphones, to the APR9600?
* Did you test your speaker separately, with an audio signal coming from an ordinary amplifier?