Audiometric Evaluations
Audiometric evaluations are a key component of a thorough diagnostic evaluation. Some dizziness and balance disorders develop hearing problems as a result of the condition. It’s important to have a comprehensive hearing assessment as part of the diagnostic process to more accurately diagnose and differentiate the source of the problem. All of our hearing tests are performed in sound booths to ensure the the most accurate results as possible.
The objective of any hearing test is to measure the threshold for tones and speech. During a hearing test, an Audiologist will place foam earphones in each ear and a headband around your forehead to hold a bone conductor in place. The foam earphones deliver sound through the air (sound waves) and the bone conductor delivers sound through small bone vibrations. Patients normally do not feel the vibration of the bone conductor during the test.
During testing, you will be instructed to respond each time you hear a soft tone presented in either ear. The Audiologist will be measuring the threshold for tones over a range of frequencies. Typically, the range is 250 to 8000 Hz, because this encompasses the frequency range necessary to understand speech and common noises and sounds.
An audiogram is produced by the testing equipment, which is a graphic representation of the data produced during audiometric evaluations. The audiogram is very useful because it provides a convenient way to visualize a patients hearing ability on a scale related to the “normal” range of hearing. Another necessary component of the hearing assessment, is speech testing.
Speech testing includes these two tests:
First, the Speech Reception Threshold (SRT) test is used to measure the lowest level at which you can repeat words. It is common to use two-syllable words with equal stress on each word for the SRT.
The second speech test, Speech Discrimination (SD), is used to access your ability to understand and repeat single-syllable words presented at a loud volume. The SD test is beneficial because it measures the amount of speech distortion you may be experiencing. At the conclusion of the hearing test, the audiologist will review the results and recommendations and answer any questions you may have about the test.
Loudness Scale
Listed below are several common sounds with the corresponding decibel (dB) output listed on the right. These decibel levels can give you an approximation of commonly heard sounds.
- Whisper 30
- Normal Conversation, Dishwasher 60
- Vacuum Cleaner 70
- Subway, Busy Street 80
- Lawn Mower 90
- Chain Saw, Snow Mobile 100
- Rock Concert 120
- Jackhammer 130
- Gunfire, Jet Engine 140
- Rock Music, Peak 150
Types of Hearing Loss
Sensorineural
This term describes hearing loss caused by a problem in the inner ear or the nerve that sends signals to the brain.
Conductive
This term describes hearing loss due to a problem with the portion of the middle ear that conducts sound from the outer ear canal to the inner ear. In these cases, the inner ear is not affected.
Mixed
This term describes hearing loss with a sensorineural and conductive component. Mixed hearing loss is caused by a problem with the conduction of sound through the middle ear and an inner ear or nerve loss.