Read the following context and choose the best option to answer the question.
Context: In this way any noise obtained by a rotating movement can offer an entire ascending or descending chromatic scale , if the speed of the movement is increased or decreased . Every manifestation of our life is accompanied by noise . The noise , therefore , is familiar to our ear , and has the power to conjure up life itself . Sound , alien to our life , always musical and a thing unto itself , an occasional but unnecessary element , has become to our ears what an overfamiliar face is to our eyes . Noise , however , reaching us in a confused and irregular way from the irregular confusion of our life , never entirely reveals itself to us , and keeps innumerable surprises in reserve .
Question: What might be true of the narrator ?
Options: 
- They hear a confused and irregular heartbeat .
 - They prefer to function without their hearing aid .
 - They closely study the effects of aural stimuli .
 - None of the above choices .


They closely study the effects of aural stimuli .