You can make special arrangements withe the testing center depending on your degree of hearing impairment. ESOL outlines the options for IELTS at
www<dot>cambridgeesol<dot>org/exams/exams-info/special-circumstances/hearing-difficulties<dot>html
which seem to include the range from using aids (e.g. hearing aids, headphones) to skipping specific sections.
Note - I can't post links yet, hence the need for you to replace <dot> with . above