Related Experiment Video
Updated: Aug 13, 2026

A Lightweight, Headphones-based System for Manipulating Auditory Feedback in Songbirds
Published on: November 26, 2012
Hearing in the parakeet (Melopsittacus undulatus): absolute thresholds, critical ratios, frequency difference limens,
Abstract:
Avoidance conditioning and the method of limits were used to measure absolute auditory thresholds, masked thresholds, and critical ratios in 4 parakeets. The same procedure was then used to study frequency difference limens in 6 additional animals. The power spectrum and "constancy of intonation" of the parakeet call were also measured and related to the absolute and differential frequency sensitivity. The mechanism of frequency analysis in the parakeet ear was considered in relation to the present results and to the anatomical and functional differences between the avian and mammalian auditory systems.
Related Concept Videos
The Cochlea
Sound Intensity Level
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
Echo
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case, then the...
Physical Assessment of the Respiratory Tract IV: Auscultation
Breath Sounds
Breath sounds are categorized into vesicular, bronchovesicular, and bronchial.
Respiratory System Abnormal Finding II: Palpation and Auscultation
Palpation Findings
During a respiratory assessment, palpation can reveal several vital abnormalities:
Perceiving Loudness, Pitch, and Location
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying...

