You're probably aware of the way in which guide dogs can help people who are blind get around in the world. Often Labradors or Alsatians, these four-legged assistants can really make a big difference in a person's life.
But dogs aren't just used to support people who have vision problems. Clever canines can also become loyal and helpful companions to people with hearing problems, as well those with physical disabilities.
Hearing dogs are trained to alert people with hearing difficulties to sound signals like sirens, doorbells, smoke alarms or ringing telephones. They also provide companionship and the bond between a person and their assistance dog is usually extremely strong.
How are hearing dogs trained?
Before a dog is trained, they are screened to ensure they have the right temperament and willingness to work. The dog's own sense of hearing is also tested.
Once appropriate pups have been chosen, they are trained for basic obedience. Socialisation and exposure to things like lifts, escalators, bicycles and traffic are also carried out.
Finally, the dogs are taught to recognise sounds and to alert their handler when they hear certain noises.
Are specific breeds used?
Many different dog breeds have been used as hearing dogs. Common breeds include Labradors and golden retrievers, as well as cocker spaniels, King Charles spaniels and miniature poodles.
What are the main hearing dog charities?
Hearing Dogs for Deaf People is the biggest hearing dog charity in the UK. Based in Buckinghamshire, it was officially launched at the Crufts Dog Show in 1982. Since that time, it has placed more than 1,500 hearing dogs in homes across the country.
HRH The Princess Royal has been supporting the charity since 1992. She said of the charity's mission: "A hearing dog offers companionship, confidence, security and independence to a person with hearing loss by alerting them to sounds."
How can I help?
Whether you'd like to sponsor a puppy, donate money or work as a volunteer, you should get in touch with Hearing Dogs for Deaf People.
The organisation regularly runs fundraising events and there are often openings available for tasks ranging from puppy socialising through to coordinating charity boxes.
How do I get a hearing dog?
Hearing dogs are in great demand, and if you're thinking one of these pups could help you, you will need to make an application.
Hearing Dogs for Deaf People accepts applications every year starting in April, and you must attend an information day at one of their centres in Buckinghamshire or Yorkshire.
You'll need to match certain criteria in order to qualify for a hearing dog. For example, you should be over 18 years of age and you must have a severe or profound hearing loss. In addition, you will need to demonstrate the motivation and ability to care for a hearing dog.
The waiting period is usually around five years and the charity works hard to reduce that as much as possible.
Throughout the waiting period, the charity's experts will assess the audiology and hearing test reports of potential recipients and you will need to spend some time at the training centre. The time spent at the centre will help to ensure that you're matched with the right dog.