1. What is the author's main purpose?

Câu hỏi :

Read the passage and do the tasks below.

A new hearing device is now available for some hearing-impaired people. This device uses a magnet to hold a detachable sound-processing portion in place. Like other aids, it converts sound into vibrations. But it is unique in that it can transmit the vibrations directly to the magnet and then to the inner ear. This produces a clearer sound. The new device will not help all hearing-impaired people only those with a hearing loss caused by infection or some other problems in the middle ear. It will probably help no more than 20 percent of all people with hearing problems. Those people who have persistent ear infections, however, should find relief and restored hearing with the new device.

1. What is the author's main purpose?