The objective of this lab is to build a digital sound recorder for human speech. You will first need to interface an external RAM to store the data. Next, you will need to design an analog circuit that interfaces a microphone to the ADC of the 9S12. Investigate the frequency components of human speech and design your system to pass these frequencies. You will also need a mechanism to play back the recorded sound, so design an audio amplifier that interfaces a DAC to a speaker. Your human interface should include buttons to trigger sound recording, stop recording, start playback, and stop playback.