The ear functions to analyze and encode a sound’s dimensions.<unk>  is responsible for avoiding the creation of multiple sound images from a sound source and its reflections. The advantages of this phenomenon are more noticeable in small rooms, decreasing as the reflective surfaces are placed farther from the listener. Central auditory system The central auditory system converges inputs from both ears (inputs contain no explicit spatial information) onto single neurons within the brainstem. This system contains many subcortical sites that have integrative functions. The auditory nuclei collect, integrate, and analyze afferent supply, the outcome is a representation of auditory space. The subcortical auditory nuclei are responsible for extraction and analysis of dimensions of sounds. The integration of a sound stimulus is a result of analyzing frequency (pitch), intensity, and spatial localization of the sound source. Once a sound source has been identified, the cells of lower auditory pathways are specialized to analyze physical sound parameters. Summation is observed when the loudness of a sound from one stimulus is perceived as having been doubled when heard by both ears instead of only one. This process of summation is called<unk>  summation and is the result of different acoustics at each ear, depending on where sound is coming from. The cochlear nerve spans from the cochlea of the inner ear to the ventral cochlear nuclei located in the pons of the brainstem, relaying auditory signals to the superior olivary complex where it is to be<unk> ly integrated. Medial superior olive and lateral superior olive The MSO contains cells that function in comparing inputs from the left and right cochlear nuclei. The tuning of neurons in the MSO favors low frequencies, whereas those in the LSO favor high frequencies. GABAB receptors in the LSO and MSO are involved in balance of excitatory and inhibitory inputs. The GABAB receptors are coupled to G proteins and provide a way of regulating synaptic efficacy. Specifically, GABAB receptors modulate excitatory and inhibitory inputs to the LSO. Whether the GABAB receptor functions as excitatory or inhibitory for the postsynaptic neuron, depends on the exact location and action of the receptor. Sound localization Sound localization is the ability to correctly identify the directional location of sounds. A sound stimulus localized in the horizontal plane is called azimuth; in the vertical plane it is referred to as elevation. The time, intensity, and spectral differences in the sound arriving at the two ears are used in localization. Localization of low frequency sounds is accomplished by analyzing interaural time difference (ITD). Localization of high frequency sounds is accomplished by analyzing interaural level difference (ILD).
Binaural fusion
Disc protrusion
Tooth fusion
Labial fusion
Ankle fusion
Four corner fusion
Condylar resorption
Retrolisthesis