1. The ear and causes of hearing loss

2. City Lit Learning objectives to describe how the ear works to identify the different types of hearing loss To explain common causes of hearing loss Relevant for: Assignment 1a The ear (deadline 30 th Nov 14)

3. City Lit What is sound? A vibrating source causes particles of air to vibrate in a wave form The sound wave varies in: - frequency (pitch) - amplitude/intensity (loudness)

4. City Lit Sound waves frequency (pitch) amplitude (loudness )

5. City Lit

6. Outer, middle and inner ear

7. City Lit Hair cells in the cochlea

8. City Lit Damaged hair cells

9. City Lit Hearing sound through air http://www.youtube.com/watch?v=stiPMLtjYAw

10. City Lit Hearing sound through the skull

11. City Lit Types of hearing loss Conductive Sensori-neural Mixed Central processing Non organic

12. City Lit Conductive hearing loss The journey of the sound waves from the outer ear to the cochlea is impeded or obstructed Can affect either the outer and/or the middle ear

13. City Lit Types of hearing loss

14. City Lit Sensori-neural hearing loss Results from damage to the cochlea and/or the auditory nerve Affects the inner ear Can affect how well a person discriminates and understands speech sounds

15. City Lit Damaged hair cells

16. City Lit Sensori-neural hearing loss

17. City Lit In groups/pairs: How many different causes of hearing loss can you think of?

18. City Lit Some causes of conductive hearing loss Wax or foreign bodies Malformation or damage to outer or middle ear Scarred or perforated eardrum Eustachian Tube dysfunction Otosclerosis Atresia Trauma Otitis Externa and Otitis Media Cholesteatoma

19. City Lit Some causes of sensori-neural hearing loss Anoxia Prematurity Mumps, Measles, Rubella Meningitis Vascular Trauma Ototoxic drugs Noise induced (NIHL) Viral Ménière’s disease Acoustic neuroma Brain tumour Neurofibromatosis (NF2) Presbyacusis (age –related ARHL) Genetic

20. City Lit Causes of hearing loss Syndromes e.g. Ushers, Downs, Treacher Collins, Alports Central processing disorders e.g. auditory processing disorder (APD) other cognitive difficulties Non-organic hearing loss e.g. malingering =deliberately faking a hearing loss psychogenic = arising from psychological factors

21. City Lit Explain to your partner 1. How do we hear (with normal hearing)? 2. What is a conductive hearing loss? What is a sensori- neural loss? 3. Why will someone with a sensori-neural hearing loss probably have difficulty distinguishing speech? 4. Draw lines on the diagram to separate the three parts of the ear

22. City Lit Useful sources Action on Hearing Loss www.actiononhearingloss.org.ukwww.actiononhearingloss.org.uk Hearing Link http://hearinglink.org/http://hearinglink.org/ Document Title