Arduino bluetooth wav player

#include "SD.h"
#define SD_ChipSelectPin 10
#include "TMRpcm.h"
#include "SPI.h"
TMRpcm music;
String voice;


void setup() {
music.speakerPin=9;
Serial.begin(38400);
if(!SD.begin(SD_ChipSelectPin))
{
  Serial.println("SD fail");
  return;
}
music.setVolume(5);
}
//-----------------------------------------------------------------------//
void loop() {
  while (Serial.available()){  //Check if there is an available byte to read
  delay(10); //Delay added to make thing stable
  char c = Serial.read(); //Conduct a serial read
  if (c == '#') {break;} //Exit the loop when the # is detected after the word
  voice += c; //Shorthand for voice = voice + c
  }
  if (voice.length() > 0) {
    Serial.println(voice);

  if(voice == "play faded")
  {
    music.play("faded.wav");
  }

  if(voice == "play hello")
  {
    music.play("hello.wav");
  }

  if(voice == "play alone")
  {
    music.play("alone.wav");
  }