Chapter 2 lecture on 1.16

Introduction to Motion

• Importance of Motion

  • Motion is fundamental to understanding various concepts in physics, including sound and speech.

  • Sound is considered a form of movement as it travels in waves.

Understanding Sound and Speech Production

• Speech Production

  • Involves managing breath and controlling air pressure.

  • Vocal folds vibrate when air pressure drives them, generating sound.

  • Speech can be characterized by various movements involving air pressure and articulation.

Key Concepts Related to Speech Movement

• Types of Speech Movements

  • Movements include narrowing of the airway, tongue movement, and lip sealing, all necessary for producing speech sounds.

• Study of Speech Movement

  • Known as Speech Kinematics, which focuses on the movement aspects of speech production.

• Instruments for Measuring Speech Movement

  • Instruments include Endoscopes, Electromyography (EMG), MRI, Doppler ultrasound, and CT scans for monitoring speech-related movements.

Definitions of Motion Concepts

• Speed

  • Defined as the distance covered by an object over a specific time period.

• Velocity

  • Describes speed with direction; vital for understanding the movement of articulators during speech production.

• Acceleration

  • Change in velocity or speed; can be positive (increasing speed) or negative (decelerating).

Impact of Speed on Speech Disorders

• Cluttering

  • Characterized by rapid speech rates, impacting comprehensibility.

• Broca's Aphasia

  • Affects motor speech planning, causing slower, more effortful speech production.

• Dysarthria

  • Motor control issues in speech muscles leading to slow speech.

• Stuttering

  • May involve irregularities in speech rhythm and rate.

Newton's Laws of Motion

• First Law (Inertia)

  • Objects at rest remain at rest, and objects in motion maintain their motion unless acted upon by an external force.

  • Vocal folds remain in place until air pressure overcomes their resistance.

• Second Law (Acceleration)

  • Acceleration is proportional to the applied force and inversely related to the object's mass.

  • The vocal fold movement relies on adequate force to overcome tension and initiate vibration.

• Third Law (Action-Reaction)

  • For every action, there is an equal and opposite reaction; applies to the vocal folds during sound production.

Key Characteristics Influencing Voice Production

• Work and Energy

  • Work is defined as force applied over a distance; energy is expended during speech production.

  • Kinetic energy relates to motion while potential energy pertains to position or configuration.

• Elasticity and Inertia in Voice Production

  • Elasticity allows the vocal folds to return to their original shape after deformation, essential for sound production.

  • Inertia maintains motion properties, enabling vocal fold vibration.

Properties of Matter Relevant to Sound

• States of Matter

  • Solids, liquids, and gases; solids have tightly packed molecules while gases have more kinetic energy allowing vibration transmission.

• Sound Transmission

  • Sound travels fastest through solids due to closely arranged molecules facilitating efficient energy transfer.

• Pressure

  • Depends on the quantity of air molecules and their motion in a given area; important for understanding airflow in vocal production.

Conclusion

• Understanding motion and its principles is essential in fields like speech pathology and voice therapy.

• Properties such as elasticity, inertia, and energy play crucial roles in sound production and clarity.