Physiological theories Flashcards
What are the three families of hearing theories?
Place theories, Frequency theories and volley theory
Who are the two main researchers in the Place Theory Family and what are their theories?
- Hemholtz - Resonant theory
2. Bekesey - Traveling Wave theory
What are the sub-categories of place theory?
Resonance and non-resonance/travelling wave theory
What is Resonance theory?
That the only part of the basilar membrane that will vibrate with a sound, is the part of the membrane that vibrates best at that frequency
What is the Traveling Wave Theory?
The membrane will always start vibrating at the base of the membrane and will travel along the membrane until it reaches the point that vibrates best at that frequency and will then stop.
What is one of the arguments against Resonance Theory?
There are no transverse fibres on the basilar membrane below 20Hz or above 20,000 Hz but the human ear can hear beyond these frequencies.
What are two of the arguments against the Traveling Wave theory?
- It is hard to place the point on the membrane because the high intensity frequencies excite such a large patch of the membrane.
- If two frequencies were to hit the membrane at the same time, the low frequency would hit the membrane before the high frequency had time to travel long the membrane causing a delay.
Who are the main researchers in the Frequency Theory Family and what are their theories?
- Rutherford - (non-analytic theory) Telephonic theory
2. Ewald and Meyer - Analytic Theory
What is Telephonic theory?
The membrane vibrates as a whole at the frequency of the wave and the nerve fibres then fire at the frequency of stimulation
What are the arguments against this non-analytic telephonic theory?
The nerve fibres cannot fire any faster than 300 action potentials per second.
We lose higher frequencies because they are always in vibration
Who is responsible for Volley Theory?
Wever and Bray
What is Volley Theory?
This theory is based off the Telephonic Theory, but instead of looking at the individual never theories, it looks at all of the nerve fibres. Not every single nerve fibre will catch every cycle of sound, but collectively they will catch every cycle. At least one fibre will catch the cycle, making the message consistent.
