A speech audiometry tests your ability to hear sounds.
Speech audiometry is an essential tool to assess hearing loss. It is usually performed for the assessment/examination of the following:
- Intensity and type of hearing loss
- Word recognition abilities
- Discomfort or tolerance to any speech stimuli
Speech audiometry also determines the maximum output of sound-amplifying devices.
What is speech audiometry?
A speech audiometry tests your ability to hear sounds. Mainly, two factors affect the sound:
- Intensity (based on their loudness)
- Speed of sound wave vibrations (tone)
Usually, the hearing occurs when sound waves stimulate the nerves of the inner ear. The sound then travels along nerve pathways to the brain.
The intensity of sound is measured in decibels (dB):
- A whisper is about 20 dB.
- Loud music (concerts) is around 80-120 dB.
- A jet engine is about 140-180 dB.
Listening to sound above 85 dB for a few hours can cause hearing loss. You may also feel pain after listening to louder sounds for a few hours.
The tone of the sound is measured in cycles per second or Hertz:
- Low bass tones range from 50 to 60 Hz.
- Shrill, high-pitched tones range about 10,000 Hz or higher.
A human can hear the sound in the range of 20-20,000 Hz only.
Speech audiometry includes two different tests:
- The first test determines how loud the speech needs to be for you to hear it.
- The other test checks your ability to grasp and distinguish different words as you listen to them.
What happens during a speech audiometry?
During speech audiometry, you need to sit in a sound booth and wear a headphone. The subsequent procedure is described below:
- After placing a headphone, you will hear a recording of a list of common words spoken at varying loudness. Simultaneously, you have to repeat those words.
- Next, the audiologist will determine your speech reception threshold or the lowest volume at which you can hear and recognize speech by making you repeat a list of words.
- Finally, the audiologist will measure your word recognition ability. They will tell you to repeat a few words after them or make you listen to a recording for you to repeat those words. This helps the audiologist to measure your ability to understand speech at a comfortable listening level.
How to interpret the test results of speech audiometry?
Normal results include the ability to hear the complete speech. For most patients with normal hearing, speech is the most comfortable at 40-50 dB above the speech reception threshold. This sensation level is reduced for many patients. The following conditions may affect test results:
- Acoustic neuroma (a benign tumor on the main nerve leading from the inner ear to the brain)
- Acoustic trauma from a very loud or intense blast sound
- Age-related hearing loss
- Alport syndrome (an inherited form of kidney inflammation characterized by kidney disease, hearing loss, and eye abnormalities)
- Chronic ear infections
- Labyrinthitis (inflammation of the part of the inner ear or labyrinth)
- Ménière’s disease (an inner ear disorder that causes vertigo)
- Ongoing exposure to loud noise, such as at work or from music
- Otosclerosis (abnormal bone growth in the middle ear)
- A ruptured or perforated eardrum