London's Tube, trains and buses do not cater for the needs of deaf passengers, according to a charity for the deaf.
Deaf people have difficulties on public transport, says the report
Many were oblivious to delays, platform alterations and station evacuations and 10% had been trapped in Tube doors because they did not hear the warning.
London Transport relies too much on audible information and the ability of passengers to use it, the report found.
Transport for London (TfL) says it is investing heavily in meeting the needs of disabled people, including the deaf.
The report, by the Royal National Institute for the Deaf and Hard of Hearing (RNID), found many Tube and train passengers felt not enough had been done to make sure emergency procedures could be followed.
Most also felt that not enough visual information was provided.
RNID chief executive John Low said: "It is really quite astounding that in the 21st century, one of the world's largest transport systems still relies almost entirely on its passengers being able to hear.
"Barriers to public transport continue to exist and the level of access deaf and hard-of-hearing people experience is still falling short of what they should reasonably expect."
A TFL spokeswoman said the organisation was working hard to improve things for disabled passengers, including deaf people and those with hearing difficulties.
She added: "Improvements coming up include more dot matrix indicators giving information on the Tube, induction loops in ticket halls and platforms, and an updated visual display system on the bus network."
By the end of the year all London bus drivers should have completed training which includes dealing with issues faced by hearing-impaired passengers.
TfL said it has also improved facilities at one-third of train stations (109 of 304) with better signage and more help points.