Acoustic Physicality vs. Perception
This physical property of a tone, measured in Hertz, determines its perceived pitch.
What is frequency?
By classroom convention, an absolute threshold is defined as the lowest sound level a listener can detect on approximately this percentage of trials.
What is 50%?
This clinical decibel scale uses frequency-specific reference thresholds derived from normal human hearing levels.
What is dB HL (Hearing Level)?
These curves map out combinations of frequencies and sound pressure levels that human listeners judge to be equal in loudness.
What are equal-loudness contours?
Abbreviated ITD, this interaural difference helps listeners localize sound based on when a wave arrives at each ear.
What is Interaural Time Difference?
While sound pressure and intensity are physical measures, this term describes the subjective human perception of sound strength.
What is loudness?
Testing in a quiet room is required during threshold evaluations primarily to prevent sound from being hidden by this.
What is background noise (or masking)?
This scale describes sound intensity relative to an individual listener's specific threshold at a given frequency.
What is dB SL (Sensation Level)?
Human hearing sensitivity varies across frequencies, showing peak sensitivity in this broad frequency range.
What is 1,000 to 6,000 Hz?
Interaural level differences (ILD) occur primarily because this physical obstacle blocks and absorbs sound arriving at the farther ear.
What is the head?
This branch of science specifically investigates the relationship between physical sound stimuli and the auditory sensations they produce.
What is psychoacoustics?
Abbreviated as JND, this term refers to the smallest detectable difference between a test sound and a reference stimulus.
What is Just Noticeable Difference?
If a patient's threshold at 1,000 Hz is 20 dB HL, a test tone presented at 50 dB HL represents this level in dB SL.
What is 30 dB SL?
This scale was developed to reflect the perceptually non-linear spacing of pitch in human hearing.
What is the Mel scale?
This perceptual phenomenon demonstrates how visual speech cues from lip movements can directly alter what a listener hears.
What is the McGurk effect?
Two listeners can hear the exact same sound wave differently because of variations in sensory reception and this internal process.
What is neural interpretation?
This upper perceptual boundary refers to the point where a sound level becomes uncomfortably loud and causes physical discomfort.
What is the threshold of pain?
A tone presented at 15 dB SL means the sound is played this many decibels above the listener’s individual threshold.
What is 15 dB?
Equal increments in Hertz do not correspond to equal steps in perceived pitch because pitch perception has this mathematical characteristic.
What is non-linear?
Together, time and level differences between the two ears provide key acoustic cues used for this perceptual capability.
What is sound localization (or spatial orientation)?
These inner-ear structures are responsible for converting mechanical sound vibrations into electrical neural signals.
What are sensory hair cells?
This essential procedure checks equipment to verify that an instrument delivers the exact physical stimulus intended.
What is calibration?
On an audiogram, 0 dB HL does not mean complete absence of sound pressure, but rather this standard reference point.
What is average normal human hearing threshold (for that frequency)?
On an equal-loudness contour, if Frequency A requires less sound pressure than Frequency B to sound equally loud, the human ear is considered to have this level of sensitivity at Frequency A
What is greater/higher sensitivity?
The outer ear structures, including the pinna and ear canal, alter sound signals prior to reaching the middle ear, demonstrating that perception relies on both peripheral anatomy and this type of processing.
What is neural interpretation (or central processing)?