According to The Hollywood Reporter, the four voice actors who make up the Family Guy cast -- Alex Borstein, Mila Kunis, Seth Green and Mike Henry -- has collectively negotiated a new salary between $175,000 and $225,000 per episode.
Hence, a patient with first degree heart block will typically have a soft first heart sound. For the same reasons a patient with variable PR interval (Mobitz I second degree AV block or third degree heart block) can have changing intensity of the first heart sound. Lyme carditis, anatomically corrected transposition and maternal lupus can all cause complete heart block.
These sounds are caused by the vibrations of the normal cardiac cycle. They may be produced by muscular action, valvular actions, motion of the heart, and blood as it passes through the heart. The first heart sound (S1) is heard as a firm but not sharp 'lubb' sound.