Two years ago, Morrison learned a benign tumour known as acoustic neuroma was causing deafness in one ear. If found early, acoustic neuromas are not life threatening, but they almost always result in profound hearing loss on one side.

Morrison's old hearing aid was cumbersome, and the sound quality was poor, especially for a singer. Many patients consider the device to be a nuisance and stop wearing it.

Now doctors think they've found a better way to improve hearing for people like Morrison who have at least some hearing. Another type of aid, called cochlear implants, are used to treat profound deafness.

The BAHA, or Bone-Anchored Hearing Aid, consists of a small titanium post that is surgically implanted into the patient's skull directly behind the deaf ear.

Once the incision is healed, a sound processor is fitted to the post to convert sound to vibrations that are delivered directly into the skull and then transmitted to the good ear.

Since Morrison had the surgery in January, and the sound processor attached in mid-April, he said his hearing has improved.

"I keep asking [singing partner] Sharon, am I in pitch?" recalled Morrison. "And she said 'yeah!'"

BAHA has been used for 15 years in patients who can't wear conventional hearing aids, such as people born without ears.

In people with single-sided deafness, though, it is a relatively new and a not well-studied treatment.

"We're in the process of assessing which patients will benefit and which won't at this point," said otolaryngologist Dr. Philip Wade. Morrison's incision looks good so far, Wade said at a recent check-up.

The cost of fitting one patient can run upwards of $20,000.

Morrison received the device free from the company in exchange for agreeing to talk publicly about his experience.

So far, Morrison said he's thrilled with the quality of his hearing. "I'm scarcely aware that it's working. The sound is very natural."

From CBC News