There was something not quite right about my baby boy. When I walked into his room to lift him out of his cot, he never seemed to hear me. Once he saw me, he would wave his arms and legs about, but was quite obliivious to the noise of the door handle and my footfalls.
So when he failed his first hearing test at seven months, I was concerned but not surprised. More than a year of medical observation followed.
Like thousands of other children, my son had a hearing problem. Put those thousands into the classroom a few years later and some may still have that problem. Or it may have cleared up, leaving speech difficulties and a short attention span in its wake. Other children miss out on schooling and suffer painful earaches because of infections.
A major cause of temporary deafness in children is glue ear. The middle ear becomes blocked by fluid, and sound cannot pass. It affects one in four children, according to the National Deaf Children's Society, and is linked to coughs, colds and earache. It tends to recur in winter.
Then there are routine ear infections, also more frequent in winter, and hearing loss caused by meningitis, mumps and measles.
There's a general impression among teachers that hearing problems are on the increase. The two chief suspects are asthma, itself far more common than a generation ago, and antibiotics.
According to Dr Deidre Lucas, consultant at the Nuffield Hearing and Speech Centre in London, antibiotics are blameless. "There's no evidence that they cause hearing loss," she says. But there does appear to be a connection to asthma.
Dr Lucas says: "There's a link between ashthma, hay fever, eczema and allergic rhinitis. They form a group, all triggered by allergies." Fitted carpets, central heating, double glazing, domestic animals have all been implicated in recent studies of asthma, adds Dr Lucas.
Mrs Diana Arlett is a teacher and special educational needs co-ordinator at Wallands county primary school in Lewes, East Sussex. It's an infant and junior school with a nursery and a speech and language section which serves a large part of the county. The school is known for being helpful to children with learning difficulties.
"We're certainly seeing a lot of asthma and a lot of children with hearing problems coming into the school, but that may simply be our reputation, " says Mrs Arlett, who has taught for 28 years.
"The majority of cases that I come across are children who have had severe hearing loss when very young, say three to five-years-old. Such children may also have behavioural problems because they fail to concentrate properly and are frustrated. Reading is delayed. Spelling is deficient because they don't hear many of the sounds."
The earlier these children have help, the better, preferably before they get to school. Mrs Arlett suggests that parents of children with any speech or language comprehension problems should go to their GP and insist on seeing a speech therapist.
Sometimes it's very simple to help such children. Pupils sitting round work tables instead of in the old-fashioned rows of desks cannot all be facing the teacher.
"If listening is an effort for a child, it's only fair to speak slowly and clearly. A child will listen better when watching the teacher's face. And a teacher should keep reminding the child to watch," says Mrs Arlett.
It was glue ear my own little boy had. With a hearing loss of 40 per cent, grommets - small tubes inserted through the drum which allow oxygen into the middle ear - seemed inevitable. Like many parents, we were fairly keen on the operation.
But there's been a change of attitude among doctors and surgeons towards grommets. With 100,000 operations a year, grommet insertion used to be the tonsillectomy of its day. But even while they operated, specialists doubted whether the operation, which requires a general anaesthetic, was necessary in most cases. Parents, they said, expected them to do something. "Wait and see" was not a popular prescription.
In some areas, such as Berkshire, health professionals have recently gone public and said they will perform far fewer operations. In some cases the operation is still necessary.
The idea today is to monitor glue ear cases instead. And that is what happened to our son. By 21 months he had outgrown the problem, though he'll be having a mid-winter check to be on the safe side.
Good news. But older children could of course miss out in the classroom while the doctors monitor them for several months to see whether an operation is necessary.
A pupil with poor hearing who isn't already being monitored can be hard to spot. The child tends to be withdrawn, sometimes playing alone and not making friends very easily. A child who is heavy-eyed, breathes through the mouth and is listless may well have an ear problem. More obvious signs are nasal speech and a tendency not to pronounce the endings of words.
There are behavioural indicators too. A deaf child who has missed what the teacher says will often watch everyone else in the class and then do the same thing minutes later. He or she may daydream and appear bored. At the other extreme, the frustration of deafness can cause aggression.
The National Deaf Children's Society issues advice to teachers. These are some of their main points.
* Use plenty of visual aids (pictures, diagrams, maps).
* Don't just tell children to, for example, finish four questions before playtime. Write the instruction on the board.
* If a child doesn't hear you first time, repeat what you say in a different way.
* Arrange the seating so the hard-of-hearing child can see you. In a class discussion, point to whoever is speaking at the moment.
* Encourage a quiet classroom. A child who can't hear will often nod, smile or say yes just to oblige. Ask your questions in a way which requires a proper answer. Then you'll know whether the child has heard.
* Don't let the child sit near a distraction, such as a window looking out over a busy street.
Advice on teaching children with hearing problems is available from The National Deaf Children's Society, 15 Dufferin Street, London EClY 8PD. Tel: 0171 250 0123. Some local education authorities also issue guidelines.