Tube drivers have voted to take industrial action over London Underground track noise levels, describing progress as "too slow".
More than 95% of RMT union members backed a ballot across the Jubilee, Central, Northern and Victoria lines.
The result, which is for action short of a strike, will be now be considered by the union's executive.
A broader range of ear protection has been offered to drivers, Transport for London (TfL) said.
RMT's General Secretary Mick Cash said it was "appalling" that members had to resort to the ballot.
"The health of our members exposed to this barrage of noise night and day is given top priority", he said.
A TfL said: "We have further meetings scheduled with union representatives and we look forward to working together to make sure that drivers are as comfortable as possible while carrying out their duties."
In 2018, the BBC used noise meters supplied by the University College London (UCL) to record sound levels at stations in zones one and two.
Dr Joe Sollini, of UCL's Ear Institute, analysed the data and said "it was concerning" .