the theory which posits that (i) various frequencies arouse various places along the basilar membrane and (ii) pitch is coded by the location of maximal arousal. The first proposition is greatly reinforced by experimental proof and stems from the fact that the mammalian auditory system reflects tonotopic order. The second hypothesis is still controversial.
Place theory in psychology
The mechanism underlying human perception of pitch is described by the place theory, a scientific hypothesis from the discipline of psychology. It suggests that certain sound frequencies are perceived at certain locations on the basilar membrane, a structure found in the cochlea of the inner ear, by human auditory system.
Georg von Békésy, a biophysicist from Hungary, first proposed this hypothesis in 1960. Sound waves are transformed into electrical impulses that the brain can recognize as sound via the basilar membrane. The idea helps to explain why certain sounds are perceived as higher or lower than others and how humans perceive different pitches.
Examples
Listening to music or having a discussion are examples of how location theory is put into practice. Your auditory system analyzes the many frequencies that are registered along the basilar membrane as you hear different pitches by locating the precise locations along the membrane. You can understand speech and enjoy melodies in music since you can notice and differentiate between different sounds thanks to this.
In order to elaborate on the context of place theory, it is important to note that the theory is just one of several hypotheses about how human auditory system interprets pitch. The frequency theory is another well-known theory that contends that the frequency of sound waves, specifically the rate at which the basilar membrane vibrates in response to these waves, controls our perception of pitch.
It is crucial to realize that both theories contribute to how we perceive sound, even if frequency theory and location theory take different approaches to understanding how we perceive pitch. In reality, recent research indicates that both hypotheses support one another, and it is likely that the brain combines both hypotheses to process sound.
It is crucial to comprehend the many theories of pitch perception in disciplines like audiology, where specialists try to identify and cure hearing abnormalities. These theories are also used by sound designers, audio engineers, and musicians to produce and alter sound in a variety of media, such as music, movies, and video games.
How do we hear according to place theory?
Place theory states that hearing is based on an examination of the precise spot on the basilar membrane where sound frequencies are picked up (von Békésy, 1960). The cochlea, which is filled with fluid, vibrates as sound waves reach the ear.
The basilar membrane, which has varied stiffness along its length, is stimulated as a result of these vibrations. The pitch we perceive is determined by the precise region of the membrane that vibrates in response to a given frequency. The auditory nerve then transmits this information to the brain, enabling us to absorb and comprehend the sounds we hear.
How does place theory explain pitch?
Place theory explains pitch perception by associating different frequencies with specific locations along the basilar membrane (von Békésy, 1960). The membrane's varying stiffness enables it to respond to different frequencies: higher frequencies cause maximal vibrations near the base (closer to the oval window), while lower frequencies cause maximal vibrations near the apex (the end of the cochlea).
By detecting the location of maximum vibration, our auditory system can determine the pitch of the sound we hear.
Place theory vs frequency theory vs temporal theory
Place theory, frequency theory, and temporal theory are three prominent theories that explain how our auditory system perceives sound, specifically pitch.
- Place theory: As discussed earlier, place theory posits that pitch perception is determined by the specific location on the basilar membrane where sound frequencies are detected (von Békésy, 1960).
- Frequency theory: In contrast, frequency theory suggests that pitch perception is based on the rate at which the auditory nerve fires in response to incoming sound waves (Wever & Bray, 1930). According to this theory, the auditory nerve generates action potentials at the same frequency as the incoming sound, allowing the brain to perceive pitch based on the frequency of neural firing.
- Temporal theory: Temporal theory, also known as the volley theory, combines elements of both place and frequency theories. This theory proposes that groups of auditory nerve fibers fire in a coordinated manner to create a "volley" of neural activity that matches the frequency of the incoming sound. This volley pattern allows for pitch perception based on both the rate of neural firing and the specific location on the basilar membrane where the sound is detected.
References
von Békésy, G. (1960). Experiments in hearing. New York, NY: McGraw-Hill. https://www.scirp.org/(S(351jmbntvnsjt1aadkposzje))/reference/ReferencesPapers.aspx?ReferenceID=1695339
Wever, E. G., & Bray, C. W. (1930). The nature of acoustic response: The relation between sound frequency and frequency of impulses in the auditory nerve. The Journal of Experimental Psychology, 13(4), 373-387. DOI:10.1037/h0075820
