Diagnostic Audiology

Diagnostic Audiology

Our professional staff of Audiologists are all Doctors of Audiology. They are fellows of the American Academy of Audiology, certified by the American Speech Language-Hearing Association and licensed by the State of California. This expertise, coupled with access to the most technologically advanced diagnostic tools and hearing aids, ensures that our patients receive the finest hearing care available.

Our team of audiologists provides unparalleled care to patients throughout the San Joaquin Valley.

Our Audiology Services Include:

  • Comprehensive diagnostic hearing evaluation
  • Counseling and aural rehabilitation 
  • Pediatric hearing management 
  • Hearing aid consultation and evaluation 
  • Dispensing hearing aids including proper fitting of a full spectrum of technology levels and styles to suit a broad range of patient’s needs

Audiology Services Staff

Jasmit Bal, Au.D.,  CCC-A

  • Doctor of Audiology- University of Florida
  • Masters Degree-Audiology, CSU, Northridge
  • Practicing with CCENT since 1998
  • Director of Audiology

Victor Colunga, Au.D., CCC-A

  • Doctor of Audiology- Arizona School of Health Sciences
  • Masters Degree-Audiology, CSU, Fresno
  • Practicing with  CCENT since 2012
  • Proficient in Spanish
  • Audiologist experience for 25+ years
  • Doctor of Audiology – Pacific University, OR
  • Practicing with CCENT since 2019

Nicholas Ottley, Au.D., CCC-A

  • Doctor of Audiology- University of Washington
  • Practicing with CCENT since 2018

What is an Audiologist?

Audiologists are health care professionals trained to evaluate, diagnose and rehabilitate persons with hearing and/or balance problems. Certified audiologists hold a Masters degree and/ or a Doctorate degree from an accredited university, and in addition, undergo rigorous state and national testing to obtain certification and licensing. The Audiologists’ specialized training makes them uniquely qualified to provide the following services:

  • Testing and diagnosing hearing and balance disorders in infants, children and adults.
  • Educating consumers and professionals on the prevention of hearing loss.
  • Selecting, fitting and dispensing hearing aids and assistive listening devices.
  • Consulting and administering help through hearing conservation programs in industry to prevent work related and recreational hearing loss.
  • Conducting research on environmental influences on hearing, new testing methods and new technologies such as cochlear implants.
  • Providing aural rehabilitation such as lip-reading and auditory training to all age groups.

At Central California Ear, Nose and Throat Medical Group, a team of certified audiologists are on staff to ensure our patients receive the finest available hearing health care.

Audiology Tests 

Diagnostic Audiogram

The audiogram is a graph which indicates specific frequencies (pure tones) and intensity levels (in decibels) which identify what a person can hear in each ear individually.  Pure tone audiometry can be accomplished with head phones or insert earphones worn by the patient.  Speech audiometry is another component of the comprehensive audiological evaluation, and this involves the patient repeating spondaic (two-syllable) words at increasingly softer volume levels in order to establish how softly they can hear speech in both ears.  Finally, speech discrimination is established for each ear to evaluate how clearly the individual can understand words delivered to each ear.  Therefore, the audiogram identifies both how softly and how clearly the patient hears.

Impedance Audiometry


Tympanometry is a test where air pressure in the ear canal is varied to test the condition and mobility (movement) of the ear drum (tympanic membrane) and is useful in detecting disorders of the middle ear.

The test is initiated by performing a visual inspection of the external auditory canal of the patient with an otoscope to evaluate the ear canal of the patient and to ensure that there is a clear path to the ear drum. A probe tip then is inserted into the ear of the individual that will change the air pressure in the patient’s ear, produce a pure tone, and measure the body’s responses to the sound and different pressures.

During the test, it is important for the patient not to speak, move, swallow, or startle. All these actions can alter the pressure in the middle ear and invalidate the test results. The sounds heard during the test may be loud and potentially startling, so a conscious effort of the patient is required to avoid a startle reflex.

If this test is being performed on a child, it may be helpful for the examiner to explain how the test will feel, and even practice or demonstrate on a doll. The more familiar a child is with what will happen and why, the less anxiety he or she will feel.

There may be some discomfort to the patient while the probe is in the ear, but no harm will result. The patient will hear a loud tone as the measurements are taken. There are no risks to the patient.

Tympanometry determines the functionality of the tympanic membrane by observing its response to waves of pressure, and measuring the air pressure of the middle ear.

The normal air pressure inside the middle ear is 100 (a very small amount). The tympanic membrane motion should appear smooth and symmetrical.

Abnormal Tympanometry results may be indicative of any of the following:

  • fluid in the middle ear
  • perforated ear drum
  • impacted ear wax
  • scarring of the tympanic membrane
  • lack of contact between the conduction bones of the middle ear
  • a tumor growing in the middle ear

Acoustic Reflex Sub-Testing

The acoustic reflex refers to the involuntary muscle contraction within the middle ear.  It normally occurs in response to high-intensity sounds.  The two muscles within the middle ear (directly behind the eardrum) are the tensor tympani and the stapedius muscles.  In response to high-intensity sounds, the tensor tympani pulls the malleus (hammer) away from the eardrum and the stapedius pulls at the stapes (stirrup), thereby helping to protect the delicate hearing mechanism of the ear.

Brainstem Auditory Evoked Response Test

The Brainstem Auditory Evoked Response (BAER) Test is also known as Auditory Brainstem Response (ABR); evoked auditory potentials; BAEP, brainstem auditory evoked potentials; or evoked response audiometry.

This test focuses on changes and responses in brain waves that are stimulated by a clicking sound to evaluate the auditory pathways of the brainstem. The test is performed by placing the patient in a reclining chair or bed. The patient is asked to relax and remain still. Electrodes are placed on the patient’s scalp, along the vertex and on each earlobe. The patient hears clicking noises or tone bursts through earphones, and the electrodes pick up the brains response and record it on a graph.
There is very little preparation needed for this test. Patients may be asked to wash their hair the night before the test. For infants and children, the physical and psychological preparation that parents can provide for this or any test or procedure depends on the child’s age, interests, previous experience, and level of trust.

There is no discomfort in the administration of this test and there are no risks involved to the patient.

This test is ordered by physicians to help diagnose nervous-system abnormalities, hearing losses (especially in low-birth weight newborns), and to assess neurologic functions.

The auditory brainstem response is found in all people and consists of five individual waves named waves I, II, III, IV, and V. Waves I, III, and V are the most robust of the wave forms. The absolute latencies and interpeak latencies of these waves are measured. In some cases, the amplitude of the individual wave forms are measured. The overall morphology of the wave forms is also evaluated. The auditory brain stem values have a normal range. This varies among patients and instruments used.

Abnormal ABR findings may consist of delays in the absolute latency times of the individual waves, or an increased latency time between waves I-V, or waves I-III, or waves III-V. Poor wave morphology is also considered to be abnormal. Abnormal findings may indicate a hearing loss, multiple sclerosis, or a stroke. In rare cases such findings may be suggestive of a benign tumor of the 8th cranial (acoustic) nerve, located in the ear canal or central pontine myelinolysis.

Otoacoustic Emmissions (OAE)

Otoacoustic emission testing, often abbreviated as OAE, DPOAE (distortion product otoacoustic emission), or TEOAE (transient evoked otoacoustic emission), is a very helpful tool in the evaluation of hearing.  OAEs are faint acoustical signals that emit from the outer hair cells located in the cochlea of the inner ear, in response to presented stimuli.  These emissions are measured by non-invasive means.  A soft pillow-like plug is placed at the opening of the ear canal.  In the middle of the plug are two speakers and a microphone for recording the responses to a pure-tone stimulus.  The responses recorded can give valuable information regarding the cochlear portion of the inner ear.

The emissions themselves are extremely soft; therefore it is important for the patient to remain as quiet and still as possible to obtain accurate measurements.  OAEs can be used with anyone, but are typically used when testing children when there is a question of possible hearing loss.  Little cooperation, other than listed above, is needed to perform this task.

OAEs in children with a normally functioning cochlea will be robust.  Adults with normally functioning cochlea will have similar results, but not quite as robust as children.

Absent or small OAEs could indicate the following:

  • Conductive hearing loss
  • Fluid behind the ear
  • Damage to parts of the cochlea (inner ear)


VNG stands for VIDEONYSTAGMOGRAPHY and it is used to record nystagmus, which is an involuntary eye movement characterized by the eye jerking back and forth. It can be generated by the peripheral vestibular system associated with each ear. What we are recording then is known as the vestibular ocular reflex. The VNG provides a permanent record of eye movements, either with eyes open or closed. The VNG has been around since the early 1940’s and is still the basic balance test that physicians will order when treating patients with symptoms of dizziness.

The VNG test administered in our facility today consists of computerized recordings which allow the examiner to use a wide sample of informative data for analysis. It utilizes a specialized camera system housed in a lightweight goggle to record the VNG data.

The VNG consists of seven basic tests. However, the term VNG is so commonly used to refer to the entire test battery that very few people know the names of the individual subtests which make up the entire VNG test battery. They include:

Gaze test: Eye movements are recorded as the patient looks straight ahead, looks to the right, looks to the left, looks up and down, with eyes open and closed. The recording is inspected for the presence of nystagmus under any of these conditions.

Saccades: The patient’s eye movements are recorded as he looks back and forth between two points in a horizontal plane. The recording is inspected for defects of saccadic eye movement.

Pendular tracking testing: Eye movements are recorded while the patient follows a slowly moving visual target. The recording is inspected for defects of pursuit eye movement.

Optokinetic test: Eye movements are recorded while the patient watches vertical stripes or a light moving horizontally at several different speeds to the right and then to the left. The recording is inspected to determine whether the nystagmus generated by this stimulus becomes stronger as the stimulus speed increases and whether it is stronger in one direction than in the other.

Positional test: Eye movements are recorded with the patient’s eyes both open and closed, after the patient has been placed in various positions. The recording is inspected for the presence of nystagmus in any position.

Hallpike maneuver: The patient is moved rapidly from sitting to the head hanging position. The recording is inspected for nystagmus following each movement.

Caloric test: Each ear is irrigated twice, once with air or water that is above body temperature and once with air that is below body temperature. Each irrigation affects the vestibular receptors of the irrigated ear and provokes a horizontal nystagmus response. The responses of the right ear are compared with those of the left ear to determine whether the sensitivities of the right and left vestibular mechanisms are equal.

The Positional, Hallpike, and Bithermal Caloric tests are usually the subtests of most interest because they are most likely to indicate whether there is some significant peripheral vestibular dysfunction. The data is a determinant of whether a person’s dizziness is caused by the ear or if it is due to some other factor such as the central nervous system.

Patients who are referred to our facility for VNG testing must not take certain medications such as anti-dizziness medication, depressants of any kind, antihistamines, etc. for a period of 48 hours prior to administration of the test. The consumption of alcohol is also prohibited. The taking of such can affect the patient’s responses on the VNG subtests. Blood pressure and heart medication can be taken without problem.

Women should not wear any makeup, as it is removed in preparation for the placement of the VNG electrodes. Patients should be counseled not to eat too heavily before administration of the test. Patients can usually drive themselves home following the test but it is always advisable for an elderly patient to have a family member accompany him at the time of his VNG appointment.