Some stroke survivors have not received any speech and language therapy in Northern Ireland, a professional body warned.
Their communication needs should be assessed within three days of an attack, the Royal College of Speech and Language Therapists (RCSLT) urged.
A third of those affected by the debilitating events were not happy with their one-to-one therapy, while almost three-quarters were satisfied with their group sessions, research by Ulster University suggested.
Alison McCullough, head of the Northern Ireland office of the RCSLT, said: "This survey once again demonstrates how crucial speech and language therapy is in supporting the recovery and rehabilitation of stroke survivors who may be having difficulty communicating or swallowing.
"It is worrying to see that some stroke survivors are still not receiving the amount of therapy that they need, with some saying they are not receiving any provision at all."
A stroke happens when the blood supply to the brain is cut off, caused by a clot or bleeding in the brain.
There are more than 100,000 in the UK each year; around one every five minutes.
The college surveyed the communication needs of 71 people in Northern Ireland after a stroke.
Nine out of 10 survivors believe that communication difficulties following their stroke have impacted hugely on their lives, the study showed, and that fewer people are now receiving speech and language therapy after a stroke than a decade ago.
Ms McCullough added: "We are calling for a Communication Lifeline to form a core part of stroke aftercare to ensure that stroke survivors have their communication assessed within 72 hours so that they can be given a means of communicating even at a basic level.
"We would also urge commissioners to ensure that the provision of specialist speech and language therapy is available throughout Northern Ireland."
Barry Macaulay, chief executive of the Stroke Association, said the therapy was important to survivors' recovery.
"The inability to communicate basic needs can be terrifying for survivors and it is essential that speech and language therapy commences in the immediate aftermath of a stroke and continues to be provided in the community on a longer-term basis to enable greater independence and well-being.
"This improves positive outcomes and empowers stroke survivors to communicate their most basic needs to carers and close family members right from the beginning.
"We support RCSLT's call for a Communication Lifeline as this would ensure a uniform approach to stroke care across Northern Ireland."