Lesson no 16:Hearing (Audition) and Balance: Short question
What are the three main parts of the ear? The three main parts are the outer ear, middle ear, and inner ear.
What is the function of the eardrum (tympanic membrane)? The eardrum vibrates in response to sound waves and transmits these vibrations to the ossicles in the middle ear.
Name the three tiny bones in the middle ear. The three bones are the hammer (malleus), anvil (incus), and stirrup (stapes).
What is the snail-shaped, fluid-filled structure in the inner ear that contains the hearing apparatus? The cochlea is the snail-shaped structure.
Where are the sound receptor hair cells located? The hair cells are located on the basilar membrane inside the cochlea.
What is the unit used to measure the loudness of sound? The decibel (dB) is the unit used to measure loudness.
Besides hearing, what other sense is the inner ear primarily responsible for? The inner ear is responsible for the sense of balance (vestibular sense).
What structure in the inner ear detects head rotation and movement? The semicircular canals detect head rotation and movement.
How does the Place Theory explain pitch perception? Place Theory proposes that different pitches (frequencies) activate different places along the basilar membrane. High frequencies cause vibrations near the base of the cochlea, and low frequencies cause vibrations near the apex.
How does the Frequency Theory explain pitch perception? Frequency Theory proposes that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a sound wave, allowing us to perceive its pitch. This works well for low-frequency sounds.
Why are both Place Theory and Frequency Theory necessary to explain human hearing? Place Theory best explains the perception of high-frequency sounds, while Frequency Theory best explains the perception of low-frequency sounds. Middle-range frequencies are explained by a combination of both.
How does bone conduction contribute to hearing? Bone conduction allows sound to be transmitted to the inner ear through vibrations of the bones in the skull, bypassing the outer and middle ear. This is why your own voice sounds different to you.
What is timbre, and what causes it? Timbre is the quality or complexity of a sound that distinguishes it from other sounds of the same pitch and loudness. It is caused by the mixture of the fundamental tone and its overtones.
How do the vestibular sacs and otoliths contribute to our sense of balance? The vestibular sacs contain otoliths (tiny crystals) that sense the pull of gravity and linear acceleration (e.g., moving forward or upward), providing information about the head’s position relative to gravity.
What is tinnitus, and what can cause it? Tinnitus is a “ringing in the ears” sensation. It can be caused by prolonged exposure to loud noise, vascular blockage, muscle spasms in the ear, or other damage to the auditory system.
How does the auditory system locate the source of a sound? The brain compares the slight differences in the time and intensity of sound waves arriving at each ear to calculate the location of the sound source.
What is the difference between the auditory canal and the semicircular canals? The auditory canal is part of the outer ear that carries sound waves to the eardrum. The semicircular canals are part of the inner ear and are involved in detecting balance and head movement.
A person experiences dizziness and nausea after spinning around. Which part of the ear is primarily responsible for this sensation? The semicircular canals are primarily responsible
A construction worker who does not use ear protection develops hearing loss for high-pitched sounds. This is most likely due to damage to the ________ in the cochlea. Hair cells (specifically those at the base of the basilar membrane, which are sensitive to high frequencies).
The pitch of a bird’s chirp is determined by the ________ of the sound wave. Frequency.
A person with conduction deafness might benefit from a hearing aid that amplifies sound. Why? Because conduction deafness involves a problem in transmitting sound vibrations to the inner ear, so amplification can help overcome the blockage or inefficiency in the outer or middle ear.
When you hear a complex sound like a musical instrument, the ________ helps you distinguish it from another instrument playing the same note. Timbre.
According to the Place Theory, a high-frequency sound would cause the greatest vibration at which part of the basilar membrane? Near the base (the end closest to the oval window).
What is the role of the oval window in hearing? The oval window is a membrane that receives vibrations from the stirrup and transmits them into the fluid-filled cochlea, initiating the traveling wave.
A person on a boat feels the sense of the boat rocking. Which structures in the inner ear are detecting this motion? The vestibular sacs (utricle and saccule) and their otoliths are detecting the linear acceleration and tilt.
