Hearing loss and audiograms. Objectives. To understand how hearing loss is measured To recognise the degree and type of deafness from an audiogram To relate a person’s audiogram to how they might understand speech Relevant for: Assignment 1 b Audiology and aural rehabilitation.
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Objectives • To understand how hearing loss is measured • To recognise the degree and type of deafness from an audiogram • To relate a person’s audiogram to how they might understand speech • Relevant for: Assignment 1 b Audiology and aural rehabilitation
Referral pathways in NHS • Over 55 • G.P examines outer ear with otoscope • If nothing abnormal detected (NAD), G.P refers direct to audiology department for hearing test (if only age-related) or to ‘Any Qualified Provider’ (AQP) • Hearing aids if appropriate • Under 55 - or over 55 and needs further examination • G.P examines outer ear with otoscope and refers to hospital ENT (ear, nose and throat) Consultant • ENT Consultant examines outer ear, takes a history, sends patient to audiology • Audiology department does hearing test and further diagnostic tests if required. • Hearing aids if appropriate
What is Any Qualified Provider - AQP? • • Patients can choose from a range of providers to get NHS hearing aids e.g. local hospital or Specsavers, Boots etc. • • Prices paid to providers are determined by the NHS.. • • Patients choose based on individual preferences and money will follow patients’ choices. • • Providers must pass a standard qualification process to ensure they meet the appropriate quality standards • However, about 20%* of the patients meeting AQP criteria will have complex needs and so require referral back • *Source: Reading Health Forum
Pure tone audiometry (PTA) • Uses ‘pure tones’ = tones of a single frequency • Measures the ‘hearing threshold‘ = the quietist sounds the person can hear • Results are used to help diagnose the type and degree of hearing loss • Results can be used to prescribe hearing aid(s)
Ways of classifying the degree of hearing loss • Hearing loss is classified as: • Normal • Mild hearing loss • Moderate hearing loss • Severe hearing loss • Profound hearing loss
The higher the line = the better the hearing mild moderate normal severe profound
Pure tone audiometry (PTA) Measuring the ‘hearing threshold‘ using pure tones at different frequencies - air conduction - bone conduction
PTA air conduction test • Pure tones presented through headphones • Measures the hearing from the outer ear, through the middle ear to the cochlea i.e. tests the whole hearing mechanism
PTA bone conduction test • Pure tones presented through a receiver placed behind the ear on the mastoid process (bone) • Bypasses the outer ear and the middle ear; sound goes to the cochlea through the skull
Why consonants matter… A _ _ _ _ u _ e _ _ _ _ i _ e _ _ o _ o _ a _ e _ i _ _ u i _ _ (vowels only)
Why consonants matter… _ llst_ d_ ntsl_k_ ch_c_l_t_ b_sc__ts (consonants only)
The cochlea • Different frequencies detected in different parts • High frequencies detected nearest to the end where the stapes joins • Excessive noise damages this part
Descriptors of hearing loss • Sensori-neural • Conductive • Mixed • Congenital • Acquired • Progressive • Fluctuating • Bilateral • Unilateral • Symmetrical • Asymmetrical • High frequency • Low frequency