Final answer:
The incorrect statement about voice production is that 'The voice is produced by the diaphragm.' The diaphragm is involved in breathing, not voice production, which is performed by the vocal cords in the larynx, affected by cord tension and airflow for pitch and volume respectively.
Step-by-step explanation:
The incorrect statement about the production of the sound called the voice is the fourth option: The voice is produced by the diaphragm. The voice is actually produced by the vocal cords in the larynx. When we speak or sing, air pushed up from the lungs causes these vocal cords to vibrate, and this vibration creates sound waves.
The pitch of the voice is determined by the tension of the vocal cords; tighter cords produce a higher pitch, while looser cords produce a lower pitch. Additionally, the volume of the voice is determined by the force of the air passing through the vocal cords, with a stronger airflow resulting in a louder sound.
In contrast, the diaphragm is a muscle that plays a crucial role in breathing by contracting and flattening to enlarge the thoracic cavity and allowing the lungs to expand during inhalation. Its role is to facilitate the flow of air into the lungs, not directly in producing the voice.