Hong Kong star Cecilia Cheung has revealed that she has been hiding that she is hard of hearing in one ear since she made her debut in 1998.

On Chinese reality show Life Is Beautiful last week, she said her eldest son, Lucas, 13, had often complained that she spoke too loudly.

However, she did not divulge that this was because of her hearing problem, as she felt he was still young and she did not want him to become troubled by it or to feel sad on her behalf.

Even with her hearing problem, she managed to take part in the second season of reality singing contest Sisters Who Make Waves, which ended in March, although she did not win in the end.

The 40-year-old single mother of three boys - besides Lucas, she also has Quintus, 10, and Marcus, two - is known to be very close to her kids.

Lucas and Quintus' father is Hong Kong actor Nicholas Tse, who was married to Cheung from 2006 to 2011, and she has never revealed who the father of Marcus is.

As Lucas is now a teen, he prefers to play it cool with his mum, she said on the show. However, he still consults her for relationship advice, as there is a girl he fancies.

She said he had asked her to teach him "how to become a good boy", but she added as a joke: "Your mother is too perfect, it will be hard for you to find a good girl."