Answer: Reduction in pitch of voice.
Explanation: There is reduction in pitch of voice. This is largely because certain illnesses inflame the vocal cords causing them to swell. When the vocal cords swell, their linear mass density reduces and this in turn reduces the frequency of sound produced and there's a reduction in pitch.
Note that the frequency of sound emitted by the vocal cords is dependent on the mass and tension of the vocal cords.
