Hearing Studies
"Hearing implants have made an incredible advance in the treatment of severe deafness. These implants are devices which transform electrical impulse into sound and stimulate the auditory nerve, in a similar manner to normal sounds in people without hearing problems".
DR. RAQUEL MANRIQUE HUARTE SPECIALIST. OTORHINOLARYNGOLOGY DEPARTMENT
What is a hearing study?
Among the fundamental explorations performed on a patient with dizziness and vertigo are those of auditory function.
This is so because since the auditory and vestibular systems share the same anatomical structure, alterations in one frequently cause deficits in the other and, in addition, certain diseases are characterized precisely by the fact that the vertigo crisis coincides with episodes of hearing loss (E. de Ménière) or the opposite (vestibular neuritis).
The precise knowledge of the patient's hearing capacity is sometimes decisive for the adoption of a more suitable therapeutic attitude.
The study of auditory function in patients with dizziness and vertigo includes a series of tests that we will mention below.
Not all of them are always performed, leaving to the doctor's criteria one or another modality of study.
When do hearing tests take place?
These tests are not bothersome and do not require special preparation. You must come to the office on the day indicated and they are performed quickly and easily.
There are no contraindications to perform them and they are even viable in young children.
Diseases in which a hearing study is requested:
- Meniere's disease.
- Hearing loss.
- Otitis.
- Vertigo.
Do you have any of these diseases?
You may need to have a hearing test
Types of hearing studies
Liminal Tone Audiometry
This is done by having the patient comfortably seated inside a soundproofed cabin and the explorer outside, both separated by a glass that allows visual contact between the two.
By means of an audiometer, pure sounds (tones) of different frequencies are generated, which are measured in Hertz (Hz.) The tones produced range from low values or low tones (250Hz., 500 Hz.) to higher or acute tones (4000Hz., 6000Hz., 8000 Hz.), including medium values, which are very important for the understanding of conversations such as 1000Hz. and 2000 Hz.
The intensity of the tone is measured in decibels (dB.) and the scanner modifies it without reaching intense values, potentially annoying for the patient.
The patient receives the sound through headphones that are placed in his or her ears simulating a conventional hearing process, which is called airway, because the sound is transmitted from the headphone, through the external auditory canal, to the eardrum, which enters into vibration starting the hearing process.
In a second moment, once the study of the tonal thresholds for each frequency in an ear by airway is finished, a similar study is carried out in the same ear, but using a vibrator applied to the bony region behind the ear.
In this case, the tone generated by the audiometer is transformed into a vibration that is transmitted through the bone until an inner ear stimulation and an auditory perception is achieved, which in this case is called bony pathway.
There are times when the magnitude of deafness in one ear is such that it forces the use of an intensity high enough to stimulate both ears simultaneously. Since this creates confusion and can lead to serious errors, a special technique of masking the unexplored ear is performed.
This consists of the simultaneous presentation of a noise, which therefore has very different frequencies of the sound spectrum in the unexplored ear, while the study of the thresholds is carried out in the other ear. This test requires a higher degree of attention than in normal conditions, but because of its value it is worth the time and effort of the patient.
The objective of liminal tone audiometry is to measure the degree of deafness in each ear and to be able to locate the portion of the ear (external, middle or internal) in which it sits.
Voice audiometry
It is performed in the same soundproof booth, but in this case the stimulus is not pure tones, but words, and the objective of the test is not only the detection of sound, but the patient repeats the word or words, and sometimes even phrases, that the explorer communicates to him and that he receives through headphones (always via air) or through loudspeakers, voice audiometry in free field.
It is a strictly qualitative assessment of hearing that allows us to analyze the ability to understand conversations.
Usually there is a strict correspondence between the value of the intelligibility threshold and the audiometric mid-tone threshold by air.
This test measures the ability to understand the spoken message and complements the tonal study.
Impedanceometry
The whole of the tympanic membrane and ossicle chain performs an adaptation of the force exerted by the sound that reaches the ear and sets it in vibration at first and optimizes the amount of acoustic energy transmitted to the cochlea.
It is done by placing a probe in the opening of the ear canal, through which a sound of variable frequency and intensity is applied, according to the interest of the study, and pressure variations that move the eardrum slightly out of its normal position.
In this probe there is also a small microphone that records the intensity of the sound reflected by the eardrum. Within this test there are two complementary parts.
The first is the study of the tympanogram or the variation of the distensibility of the eardrum-oskeleton system as a function of the pressure exerted in the external auditory canal.
It is automatically represented graphically by a tent shaped curve, whose horizontal axis is the pressure applied in the outer ear. Under normal conditions, the peak of the curve is centered at 0 mm of pressure.
It is a specific test of the functioning of the middle ear.
The second part of the test is the study of the stapedial or stapes reflex consisting of a contraction of this muscle (analysed by changes in the tympanogram) when the ear is stimulated with a sound of 80 dB. above the threshold by air.
Auditory evoked potentials
By means of an electrical recording similar to that of the electroencephalogram, the course of the auditory stimulus can be followed through the brain or central auditory pathway.
This test is performed using a sound stimulus similar to a click that is repeated many times very quickly and at different intensities.
It reaches the patient through an earphone, airway, and the response is recorded by means of electrodes arranged precisely in the vicinity of the ear and skull.
This response must be filtered and amplified resulting in a curve with a series of peaks that reflect the passage of the nerve stimulus (resulting from the activation of the inner ear cells and the auditory nerve endings) through the various stations of the auditory pathway in the brain.
Where do we do it?
IN NAVARRE AND MADRID
The Department of Otolaryngology
of the Clínica Universidad de Navarra
The Department of Otorhinolaryngology of the University of Navarra Clinic is a national and world reference in numerous highly specialized surgical procedures.
We have the latest technology and we perform all diagnostic tests in less than 48 hours in order to offer our patients the best solution in the shortest time possible.
We were one of the first centers in Spain to use robotic surgery in the surgical treatment with the Da Vinci® System.
Organized in specialized units:
- Otology - Hearing.
- Rhinology - Nose.
- Pharyngology - Throat.
- Laryngology - Voice.
- Balance disorders.
- Head and neck problems.
Why at the Clinica?
- Experts in the treatment of hearing problems.
- Pioneers in axillary surgery to avoid scarring.
- National reference center in tissue sealing for tonsil removal.
Our team of professionals
