This interactive simulation demonstrates the principle of Cochlear Tonotopy, which is the spatial arrangement of where different sound frequencies are processed within the inner ear (the cochlea).
Key Features for the User
Anatomical Accuracy: The simulation represents the Basilar Membrane inside the cochlea. Note how the visual frame changes: the Base is narrow and stiff, while the Apex is wide and flexible.
Spatial Frequency Mapping: By moving the slider, you shift the "Peak" of the traveling wave.
High Frequencies (8000 Hz): Cause maximum vibration at the Base.
Low Frequencies (250 Hz): Cause maximum vibration at the Apex.
Synchronized Audio: When you click "Start Sound Feed", a sine wave oscillator generates the exact frequency displayed on the screen. The speed of the visual wave animation also scales with the frequency, providing a cohesive audio-visual experience.
Dynamic Envelope: The blue waveform uses a Gaussian envelope to show how the ear "tunes" to specific frequencies, with the vibration being most intense at the specific location corresponding to that pitch.
Scientific Context
In a real human ear, this physical separation allows the brain to determine the pitch of a sound based on which hair cells along the membrane are firing. This is known as the Place Theory of Hearing.
Note on Sound: Due to browser security policies, you must interact with the Start Sound Feed button before the audio context can be activated. If you hear no sound, ensure your system volume is up and the button has turned red.
Quick Reference:
Base: Handles "treble" (high pitches).
Apex: Handles "bass" (low pitches).
Traveling Wave: The wave moves from base to apex, but reaches its maximum amplitude only at the point where the membrane's natural resonance matches the sound frequency.