Answer:

Speech sounds are produced by a set of essential organs collectively known as speech organs or vocal organs. These organs play an active role, starting from inhaling and exhaling air from the lungs to shaping the air into distinct speech sounds using articulators. By studying these speech organs, we can understand the specific contribution of each organ, including the lungs, vocal folds, and articulators, in the production of the speech sounds required for effective communication.

These organs are divided into three groups. Those are —

• The respiratory system: Lungs, Muscles, Bronchial Tube, Trachea. 
• The phonatory system: Larynx, Vocal Cords. 
• The articulatory system: Nose, Mouth, Teeth, Tongue, And Lips.

The organs which are used to produce speech sounds are called speech organs. The different parts of the speech organs are described below:

1. Lungs:
   The lungs are spongy organs with alveoli, located in the chest. Inhaling draws air through the trachea into the bronchial tubes. Lung muscles expand and contract with airflow, creating the pulmonic airstream mechanism. This generates speech sounds (egressive airstream) and non-linguistic sounds like snoring (ingressive airstream). Lungs in the rib cage control pressure via airflow and energy release.

2. The Larynx & the Vocal Folds:
   The larynx, situated behind Adam’s apple, serves as the sound box and  plays a pivotal role in producing various sounds. It contains vocal cords, also called vocal folds, which can be held together like arytenoid cartilages for producing voiced sounds, or held wide apart to allow free airflow and produce voiceless sounds like /f/, /s/, and /p/. The glottis, the opening between the vocal cords, varies in states to create different sounds:
   • voiced (close and vibrating), 
   • voiceless (pulled apart), 
   • murmur/breathy voice (vibrating while apart), and 
   • creaky voice (tightened arytenoids for vibration).

Different glottis states lead to the production of various sound types.

3. Pharynx:
   The pharynx is a tube about 7 cm long in women and 8 cm in men, located above the larynx. It connects the mouth to the upper respiratory tract and is divided into oral and nasal cavities. The soft palate controls its opening and closing, affecting sound production. Together with the mouth and nose, this forms the vocal tract.
   
   Now we can divide pharynx in terms of oral and nasal cavity. 
   
   • Oral Cavity
     Oral sounds are produced  when the velum is raising and completely closing the nasal cavity. The various organs of the oral cavity are as follows:
     • Upper jaw: It consists of the upper teeth, upper lip, palate, and uvula.
     • Lower jaw: It consists of the lower teeth, lower lip, and tongue.
     • Palate: It is a roof like structure which is hard and it separates the mouth from the nose.
       
       The palate can be divided into three sections: 
       • the alveolar ridge or teeth ridge, 
       • the hard palate, and 
       • the soft palate or velum. Hanging down from the velum is a structure known as the uvula.
   • Nasal Cavity
     The nose and nasal cavity play a vital role in speech despite not being active sound producers. They consist of a cavity with two nostril openings. Nasal sounds like /M/ and /N/ are produced through the nose. This structure can also be viewed as a speech organ, as it contributes to generating nasal sounds.

6. The Roof of the Mouth: The roof of the mouth is considered as a major speech organ. It is divided into three parts:
   1. Soft palate or Velum: The soft palate in the mouth can be lowered or raised, controlling airflow into the nasal cavity. When the tongue touches its lower side, it creates velar sounds like /k/ and /g/, essential for speech production.
   2. Hard palate: The hard palate, or “roof of the mouth,” features a curved surface sensed by the tongue and produces palatal consonants like /j/ in ‘yes’. Positioned centrally, it forms a concave structure.
   3. Alveolar Ridge: The alveolar ridge, located just behind the upper front teeth and the hard palate, can be felt with the tongue due to its rough surface and ridges. Sounds like /t/, /d/, and /n/ are referred to as alveolar sounds because they are produced by touching this convex area.

7. Tongue
   The tongue is a crucial articulator used for producing speech sounds. It can be moved to various places and shapes, aiding other articulators in their functions. The tongue has distinct sections: 
   • Tip: The farthest point of the tongue.
   • Blade: Positioned opposite the alveolar ridge.
   • Front: Situated opposite the hard palate.
   • Back: Found opposite the soft palate or velum.
   • Root: The innermost part of the tongue, located inside the mouth behind the lower teeth.

Together, these tongue parts contribute to the generation of a wide range of speech sounds.

8. Teeth
   Teeth are vital for speech and are divided into upper and lower sets in the mouth. They’re positioned behind the lips and contribute to dental sounds like /θ/ and /ð/, formed when the tongue interacts with the upper teeth. These sounds are crucial for speech.
   
9. Lips
   Lips serve multiple functions in speech production. They are utilized for creating various sounds, such as the closure for /p/ and /b/, contact with teeth for /f/ and /v/, and rounding for vowel (u:). Bilabial sounds result from lip collaboration, while the contact of lips and teeth forms labiodental sounds. Furthermore, lips play a crucial role in articulation by being pressed together or contacting teeth.