The animal's hearing may in fact have been diminishing over time, but the owner may have been unaware because the animal compensated until it reached a point where it could no longer hear adequately to get by. To the owner the onset appears sudden, but it has been progressive. This is common in older animals with presbycusis (age-related hearing loss), which is progressive with time and cannot be prevented or reversed. Click here to go to a site at the web page of the National Institute on Deafness and Other Communication Disorders of the NIH on presbycusis.
People who experience a sudden hearing loss (SSNHL) are often treated with systemic steroids, which are taken orally. Studies however show that people with sudden sensorineural hearing loss (SSNHL) who do not respond to this treatment can benefit from intratympanic steroid injections. Studies carried out at universities in USA and Thailand show intratympanic steroid injections to be very effective and that the treatment does not have any side-effects.
Dr. David Haynes from Vanderbilt University Medical Center, Nashville, USA, carried out the study of 40 people who had experienced sudden sensorineural hearing loss (SSNHL). Overall, 40% showed some kind of improvement when treated with intratympanic steroid injections.