'A' Level Medical Option Questions - The Ear
(a) The graph shows the equal loudness curve for the threshold of hearing.
(i) On the diagram sketch the equal loudness curve which has an intensity level of 120 dB at a frequency of 1000 Hz. (120 phon)
General shape flatter, but still dipping at approx the same frequency and passing through pont 120, 1000
(ii) What is the main similarity between the two curves?
Both most sensitive at about 3000 Hz
(b) On the axes below draw the curves for:
(i) age-related hearing loss and label it A,
(ii) noise-induced hearing loss and label it B.
(iii) What is the main difference between the two types of hearing loss?
Loss due to age increases steadily with frequencywhereas loss due to noise produces a sensorineural loss as a 'dip' at 4,000 Hz
(Total 6 marks)