Hearing Flashcards
What is the definition of sound?
Pressure waves in the are producing by a vibrating object, which are detected by the auditory system
What is the distal stimulus of sound?
Vibrating object
What is the proximal stimulus of sound?
Pattern of kinetic energy at the eardrum
What is the phase?
Point along the wave measured in degrees
What is the perceptual counterpart to phase?
There is no direct perceptual counterpart
What is the amplitude?
The displacement of a wave from peak to trough
For large ranges, a logarithmic scale is easier to work with
What is the frequency?
The number of sound wave cycles per second in Hz
What is loudness?
The perceptual experience of sound intensity
Related to amplitude and sound pressure
What is 1 sone of loudness?
100 Hz pure tone at 40 dB
How do we double loudness?
Increase dB by 10 dB
What is pitch?
Quality of sound ranging from low to high; allows sounds to be ordered on a musical scale
Associated with frequency
Short duration will be heard as a click
What is the fundamental frequency?
Lowest frequency in a Fourier spectrum of complex sound wave
What are harmonics?
Components of a complex sound having frequencies that are multiples of the fundamental
The number and amplitude of harmonics contribute to the timbre of a sound
What is timbre?
Character or nature of a sound
Due to different frequency components produced by a vibrating source stimulus
What is the audibility curve?
Describes the absolute threshold for hearing each different frequency
What is the auditory response area?
The dynamic range of intensities from threshold to pain
What is the equal loudness curve?
Graph of decibel levels of various frequencies that seem equally loud
How do we determine the equal loudness curve?
Present standard: 1000 Hz tone at a certain dB level
Adjust intensity of other frequencies to match loudness of standard
What is the equal loudness curve also affected by?
Auditory adaptation
Auditory fatigue
What is auditory adaptation?
Same sound seems softer if presented for a long time
What is auditory fatigue?
Temporary hearing loss due to high intensity sounds
What is the pinna?
The ear on the side of your head
Channels certain sound waves into the ear canal
What is the external auditory meatus?
The ear canal
Protects the middle and inner ears
Amplifies frequencies 2000 to 5000 Hz via resonance
What is the tympanic membrane?
The eardrum
Struck by sound waves and vibrates
Transmits sound to structures in the middle ear
What are the ossicles?
Malleus, incus, stapes; supported by middle-ear muscles
Concentrates vibration of the eardrum to the oval window
Increases pressure by a 20:1 ratio
Acts as levels, increasing vibration
What is the eustachian tube?
Equalizes middle ear pressure with outside
What are the semicircular canals?
Snail-shaped structure, filled with cochlear fluid, divided into canals
-Scala vestibuli
-Scala tympani
-Scala media
What is the scala media formed by?
Basilar membrane and Reissner’s membrane
What is the tectorial membrane?
Overhangs the basilar membrane, contains 15000 hair cells