This document discusses central auditory processing and its components. It begins with definitions of central auditory processing as the brain's processing of sounds between the inner ear and brain. It then describes the key characteristics of sound including pitch, loudness, and quality. The document outlines the peripheral auditory pathway from the outer ear to the brain. It identifies the main processes of central auditory processing as awareness, discrimination, identification, and comprehension. It provides details on each process and how the brain performs these functions to understand sounds.

1. Audiology Notes
Central Auditory
Processing
DR. I. MUSAH
DEPT. OF HUMAN PHYSIOLOGY, FACULTY OF BASIC MEDICAL SCIENCES, COLLEGE OF
MEDICAL SCIENCES,111 AHMADU BELLO UNIVERSITY, ZARIA
1

2. Introduction
 The ear is an organ important in two major sensory systems; the vestibular
system involved in balance and spatial positioning in relation to the
environment and the Auditory system important in receiving sound from
the environment.
2

3. Definition
 Central Auditory processing can be defined as what the brain does, with what
the ear hears. It is describes as what happens to sound between the Organ of
Corti and the Brain.
3

4. Characteristics of Sound
 Sound is Produced by vibrations at different speeds (frequency) and propagated
through a medium (air or bone). For human speech, sound is produced by vibrations
from the vocal cord, frequency of which is 20 – 20000Hz. The physical properties of
sound, determine its characteristics.
 Pitch: This is a characteristic that distinguishes sound as grave or flat. It depends on the
frequency of the sound, with high frequency determined as higher pitch, and lower
frequency determined as low pitch sounds.
 Loudness: This is the perception of how strong the sound is at a particular place. It is
measured in decibels and it increases with amplitude
 Quality: This is the quality that allows the ear to distinguish between sounds that have the
same pitch and loudness, in other wards the shape of the wave.
4

5. PERIPHERAL AUDITORY PATHWAY
 EXTERNAL EAR
 PINNA
 EXTERNAL AUDITORY CANAL
 TYMPANIC MEMBRANE
 MIDDLE EAR
 OSSICLES + Muscles (tensor tympani and stapedius)
 Eustachian tube
 Oval window
 INNER EAR
 Vestibule (Semi circular canals, saccule and
 Cochlear
 Scala (vestibula, media & tympani), Organ of corti and spiral nerve/ganglion
 Vestibulocochlear Nerve
5

6. Central Auditory Pathway 6

7. AUDITORY PROCESSING INVOLVES
THE FOLLOWING PROCESSES
 AWARENESS
 DISCRIMINATION
 IDENTIFICATON &
 COMPREHENSION
7

8. awareness
 This describes the ability to detect sound/ identify the presence or absence
of sound. The external and middle ear are necessary for this to occur, and
problems with this process is referred to as Deafness.
8

9. discrimination
 Auditory discrimination is the ability to recognize similarities and differences between
sounds. Particularly, auditory discrimination allows people to distinguish between
phonemes in words. Phonemes are the smallest units of sound in any given language.
Auditory discrimination allows a person to tell the difference between words and
sounds that are similar as well as words and sounds that are different.
 This is possible due Basilary tuning at the level of the cortex, the arrangement of relay nuclei in the
Central auditory pathway and the Tonotopic arrangement of the auditory cortex.
9

10. Basilary Tuning
10

11. identification
 Identification is the ability to label by repeating, pointing to or writing the speech
stimulus heard.
 Identification involves the suprasegmentals & segmentals of speech.
 Suprasegmentals include speech patterns such as: duration, loudness, pitch, rhythm,
stress, or intonation.
 Segmentals are the vowels and consonants in speech. Segmentals include: initial sounds
of words, words varying in number of syllables, one syllable words that differ in vowels
and consonants, and stereotypic messages such as familiar expressions or directions
11

12. comprehension
 Comprehension is the ability to understand the meaning of speech by answering
questions, following directions, paraphrasing, or participating in a conversation. It is
demonstrated by a child when his/her response is qualitatively different than the
stimuli presented.
 Comprehension requires auditory memory and follows an auditory sequence:
 Familiar expressions and common phrases
 Following single directions and two directions
 Following classroom instructions
 Sequencing three directions
 Comprehension of multi-element directions
 Sequencing three events in a story
 Answering questions about a story: closed set and open sets
 Listening in noise
 Description of environmental sounds
12

13. Conclusion 13