For the purposes of this guidance, severe to profound deafness is defined as hearing only sounds that are louder than 80 dB HL (pure-tone audiometric threshold equal to or greater than 80 dB HL) at 2 or more frequencies (500 Hz, 1,000 Hz, 2,000 Hz, 3,000 Hz and 4,000 Hz) bilaterally without acoustic hearing aids. Adequate benefit from acoustic hearing aids is defined for this guidance as:
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for adults, a phoneme score of 50% or greater on the Arthur Boothroyd word test presented at 70 dBA
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for children, speech, language and listening skills appropriate to age, developmental stage and cognitive ability. [2009, amended 2018]
NHS England has three months to implement the guidelines from the date of publication of the guidance.