TMRpcm Slow Audio Play Back

I have hooked up a micro sd card to the Arduino pro mini. I am using the TMRpcm library to play the wav files that I have converted to 8 bits 32khz and mono, as instructed. I can get the audio to play but the speech is slowed down by at least a factor of 2 or more. Any ideas on what I've done wrong?

Heres the code I am using:

#include                       // need to include the SD library
//#define SD_ChipSelectPin 53  //example uses hardware SS pin 53 on Mega2560
#define SD_ChipSelectPin 10  //using digital pin 4 on arduino nano 328, can use other pins
#include            //  also need to include this library...
#include 

TMRpcm tmrpcm;   // create an object for use in this sketch


void setup(){

  tmrpcm.speakerPin = 9; //5,6,11 or 46 on Mega, 9 on Uno, Nano, etc

  Serial.begin(9600);
  if (!SD.begin(SD_ChipSelectPin)) {  // see if the card is present and can be initialized:
    Serial.println("SD fail");  
    return;   // don't do anything more if not
  }
  tmrpcm.quality(1);
  tmrpcm.volume(2);
  tmrpcm.play("1.wav"); //the sound file "music" will play each time the arduino powers up, or is reset
}



void loop(){  

  if(Serial.available()){  
    if(Serial.read() == 'p'){ //send the letter p over the serial monitor to start playback
      tmrpcm.play("1.wav");
    }
  }

}

I fixed the problem. It turns out that this library needs a 16 MHz processor to run. I switched it over and it worked fine.