Pure Tone Audiometry & Tympanometry at Chughtai Lab

Pure Tone Audiometry (PTA) & Tympanometry (Tymp) at Chughtai Lab

Pure Tone Audiometry (PTA) and Tympanometry (Tymp) are fundamental diagnostic evaluations in audiology used to comprehensively assess an individual’s hearing sensitivity and middle ear function. At Chughtai Lab, Pakistan’s leading diagnostic network, these tests are offered as a combined audiological profile, particularly optimized for corporate health packages, pre-employment screenings, and occupational health monitoring. Hearing conservation is a critical component of occupational safety, especially for industries involving high noise levels, such as manufacturing, aviation, construction, and telecommunications. By combining subjective hearing assessments with objective middle ear measurements, this diagnostic panel provides a complete overview of an individual’s auditory health.

Pure Tone Audiometry is a subjective behavioral test used to measure hearing threshold levels. It determines the faintest sounds a person can hear at different frequencies (pitches), ranging from low to high tones. The test evaluates both air conduction (how sound travels through the ear canal, eardrum, and middle ear bones to the inner ear) and bone conduction (how sound vibrations travel directly through the skull bones to the cochlea). This dual approach allows audiologists to pinpoint the exact nature of any hearing impairment. Tympanometry, on the other hand, is an objective, physiological test that measures the acoustic admittance or compliance of the middle ear system as air pressure in the external auditory canal is varied. It does not measure hearing sensitivity directly but evaluates how well the tympanic membrane (eardrum) and the middle ear ossicles (malleus, incus, and stapes) respond to pressure changes, helping to identify physical blockages, fluid accumulation, or structural damage.

The clinical importance of these combined tests lies in their ability to detect early signs of hearing loss, particularly Noise-Induced Hearing Loss (NIHL), which often begins silently at higher frequencies before affecting daily communication. For corporate clients, implementing routine audiological screenings through Chughtai Lab ensures compliance with occupational health standards, protects employees from progressive hearing damage, and assists in the proper placement of personnel in appropriate working environments. This comprehensive diagnostic profile serves as an essential tool for early intervention, preventing irreversible auditory damage, and maintaining overall employee well-being.

Clinical Procedure: What to Expect

Patient Preparation

To ensure highly accurate and reliable results during the Pure Tone Audiometry and Tympanometry evaluations at Chughtai Lab, patients must adhere to specific preparation guidelines:

• Avoid Loud Noise Exposure: Patients must avoid exposure to loud noises (such as heavy machinery, concerts, personal audio devices at high volume, or firearms) for at least 14 to 16 hours prior to the test. This “noise holiday” is critical to prevent a temporary threshold shift (TTS), which can artificially worsen hearing test results.
• Ear Canal Clearance: A preliminary otoscopic examination should ideally be performed. If significant cerumen (earwax) impaction, discharge, or foreign bodies are present in the external auditory canal, they must be professionally cleared before testing, as earwax can block sound waves and alter tympanometry readings.
• No Special Fasting Required: There are no dietary restrictions or fasting requirements for this test. Patients can eat, drink, and take their regular medications as prescribed.
• Report Symptoms: Patients should inform the audiologist if they are currently experiencing symptoms of a cold, sinus congestion, ear pain, active discharge, or severe tinnitus, as these conditions can temporarily affect middle ear pressure and hearing thresholds.
• Remove Accessories: Before entering the testing booth, patients will be asked to remove eyeglasses, large earrings, headbands, or head coverings that might interfere with the proper placement and seal of the audiometric headphones or tympanometry probe.

During the Procedure

The combined audiological assessment is conducted in a quiet, controlled environment by a qualified audiologist or trained technician at Chughtai Lab. The procedure is entirely non-invasive, painless, and typically completed within 20 to 30 minutes.

Phase 1: Tympanometry (Middle Ear Assessment)
The test usually begins with tympanometry. The patient is seated comfortably. The clinician selects an appropriately sized, soft plastic probe tip and inserts it gently into the opening of the ear canal to create an airtight seal. A low-frequency probe tone (typically 226 Hz for adults) is presented while the pump inside the tympanometer varies the air pressure within the ear canal from positive to negative limits. The instrument measures how much sound energy is reflected back from the eardrum, recording the compliance of the middle ear system on a graph called a tympanogram. The patient will feel a mild sensation of pressure changes in the ear, similar to changing altitudes in an airplane, but no pain. This phase takes only 1 to 2 minutes per ear.

Phase 2: Pure Tone Audiometry (Hearing Threshold Assessment)
For the second phase, the patient is seated inside a specialized, sound-treated audiometric booth designed to eliminate ambient environmental noise. The clinician places calibrated supra-aural (over-the-ear) or insert headphones on the patient. The patient is instructed to remain still and quiet, and to respond (by pressing a hand-held button or raising a hand) every time they hear a tone, no matter how faint or brief it may seem. The audiologist presents pure tones at various frequencies (usually 250, 500, 1000, 2000, 4000, and 8000 Hz) to establish the air conduction thresholds for each ear individually. Following this, a bone conduction oscillator (a small vibrating device on a metal headband) may be placed on the mastoid bone behind the ear to measure bone conduction thresholds, bypassing the outer and middle ear to test the inner ear directly. The patient’s responses are plotted on an audiogram, which displays hearing thresholds in decibels (dB) across the frequency spectrum.

When is a Pure Tone Audiometry & Tympanometry Performed?

Occupational Health & Corporate Screening

In industrial and corporate settings, employees are frequently exposed to hazardous noise levels. Physicians and corporate health officers request this combined test as part of pre-employment medical examinations and annual surveillance programs. Regular monitoring helps detect early signs of noise-induced hearing loss, allowing companies to implement protective measures, adjust hearing conservation protocols, and comply with national and international labor safety regulations.

Evaluation of Unexplained Hearing Loss

When an individual reports a subjective decline in hearing sensitivity, difficulty understanding speech in noisy environments, or a feeling of muffled sound, a physician will order a PTA and Tympanometry. The combined results help determine whether the hearing loss is conductive (arising from the outer or middle ear), sensorineural (resulting from damage to the inner ear or auditory nerve), or mixed (a combination of both), which is essential for guiding medical or surgical treatment.

Investigation of Middle Ear Pathology

Tympanometry is specifically indicated when a patient presents with symptoms of middle ear pressure, fullness, pain, or fluid sensation. It is highly effective in diagnosing conditions such as otitis media with effusion (fluid behind the eardrum), Eustachian tube dysfunction, tympanic membrane perforation, or ossicular chain discontinuity, providing objective physical data to complement clinical findings.

Tinnitus Assessment

Tinnitus, characterized by ringing, buzzing, or hissing sounds in the ears, is often a symptom of underlying auditory system dysfunction. Physicians request PTA and Tympanometry to investigate the presence of coexisting hearing loss or middle ear pressure abnormalities that may be contributing to or exacerbating the tinnitus, helping to formulate an appropriate management plan.

Pre- and Post-Treatment Monitoring

For patients undergoing medical or surgical interventions for ear disorders—such as tympanoplasty, middle ear fluid drainage, or treatment with ototoxic medications (which can damage hearing)—these tests are performed before and after treatment. This allows clinicians to objectively monitor changes in hearing thresholds and middle ear function over time to evaluate treatment efficacy.

What Does a Pure Tone Audiometry & Tympanometry Detect?

The combined diagnostic findings from Pure Tone Audiometry and Tympanometry can identify a wide range of physiological and pathological conditions affecting the auditory system, including:

• Normal Hearing Sensitivity: Hearing thresholds across all tested frequencies fall within the normal range (0 to 25 dB HL).
• Mild Sensorineural Hearing Loss: Difficulty hearing faint sounds, often affecting high frequencies first, commonly due to aging or early noise exposure.
• Moderate Sensorineural Hearing Loss: Difficulty understanding speech, particularly in background noise, requiring higher volume levels.
• Severe to Profound Hearing Loss: Inability to hear most conversational speech, requiring significant amplification or assistive devices.
• Conductive Hearing Loss: Sound transmission is blocked in the outer or middle ear, while inner ear function remains normal.
• Mixed Hearing Loss: A combination of both conductive and sensorineural hearing impairments in the same ear.
• Noise-Induced Hearing Loss (NIHL): Characterized by a classic “audiometric notch” typically at 4000 Hz on the audiogram.
• Presbycusis: Age-related, gradual, bilateral high-frequency sensorineural hearing loss.
• Type A Tympanogram (Normal Middle Ear Function): Indicates normal eardrum mobility and normal middle ear pressure.
• Type As Tympanogram (Stiff Middle Ear System): Normal pressure but reduced compliance, often associated with otosclerosis or scarring of the eardrum.
• Type Ad Tympanogram (Highly Compliant Middle Ear System): Normal pressure but excessively high compliance, suggesting ossicular discontinuity or a flaccid eardrum.
• Type B Tympanogram (Flat Trace – Low Volume): Indicates restricted eardrum mobility, commonly caused by middle ear effusion (fluid), otitis media, or a tumor.
• Type B Tympanogram (Flat Trace – High Volume): Indicates a perforation in the tympanic membrane or a patent tympanostomy tube.
• Type C Tympanogram (Negative Middle Ear Pressure): Indicates Eustachian tube dysfunction, often seen with colds, allergies, or sinus infections.
• Eustachian Tube Dysfunction: Inability of the Eustachian tube to adequately equalize pressure between the middle ear and the atmosphere.
• Otitis Media with Effusion (OME): Accumulation of non-purulent fluid in the middle ear cleft.
• Tympanic Membrane Perforation: A physical tear or hole in the eardrum.
• Otosclerosis: Abnormal bone growth in the middle ear that immobilizes the stapes bone, leading to conductive hearing loss.
• Ossicular Discontinuity: Disconnection of the tiny bones in the middle ear, often due to trauma or chronic infection.
• Acoustic Neuroma (Vestibular Schwannoma): A benign tumor on the auditory nerve, often presenting with asymmetrical sensorineural hearing loss.
• Meniere’s Disease: An inner ear disorder characterized by fluctuating low-frequency hearing loss, episodic vertigo, and tinnitus.
• Ototoxicity: Inner ear damage caused by certain medications, presenting as bilateral high-frequency hearing loss.
• Barotrauma: Injury to the middle ear caused by rapid changes in ambient air pressure (e.g., scuba diving or flying).
• Cerumen Impaction: Significant buildup of earwax causing a temporary conductive hearing loss and altered tympanometric volume.
• Asymmetrical Hearing Loss: A significant difference in hearing thresholds between the left and right ears, requiring further neurological investigation.

Turnaround Time and Report Access at Chughtai Lab

Chughtai Lab is committed to providing rapid, accurate, and highly accessible diagnostic reporting. For Pure Tone Audiometry and Tympanometry, the raw data is recorded and plotted immediately during the testing session. The final formalized report, containing the plotted audiogram, tympanometric curves, and an expert audiologist’s interpretation, is typically compiled and verified within a few hours of the procedure.

Patients and corporate clients can access their diagnostic reports conveniently through multiple digital channels. Reports can be downloaded directly from the official Chughtai Lab website using the patient’s unique lab ID and password provided on the receipt. Additionally, Chughtai Lab offers a dedicated mobile application where patients can view, download, and archive their entire medical history. For corporate clients, consolidated occupational health reports can be securely transferred via corporate portals or email, ensuring seamless integration into employee health records.

Pure Tone Audiometry & Tympanometry Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Air Conduction Thresholds (PTA)	Thresholds between 0 and 25 dB HL across all frequencies (250 – 8000 Hz).	Thresholds > 25 dB HL, indicating mild, moderate, severe, or profound hearing impairment.
Bone Conduction Thresholds (PTA)	Thresholds match air conduction thresholds within 10 dB, indicating no conductive barrier.	Thresholds significantly better than air conduction (Air-Bone Gap > 10 dB), indicating conductive or mixed hearing loss.
Middle Ear Pressure (Tympanometry)	Peak pressure between -100 and +50 daPa (Type A).	Negative pressure < -100 daPa (Type C), indicating Eustachian tube dysfunction.
Static Compliance (Tympanometry)	Compliance between 0.3 and 1.5 ml (or cm³).	Reduced compliance < 0.3 ml (Type As) or excessive compliance > 1.5 ml (Type Ad).
Ear Canal Volume (ECV)	Physical volume between 0.6 and 2.0 ml (adults).	Very low volume (obstruction/wax) or abnormally high volume > 2.0 ml (Type B with perforation).
Tympanogram Shape	Symmetrical, single-peaked curve centered near atmospheric pressure (Type A).	Flat line (Type B) or shifted peak (Type C), indicating fluid, perforation, or pressure issues.
Symmetry Between Ears	Symmetrical hearing thresholds and middle ear compliance in both ears.	Asymmetric curves or thresholds, indicating unilateral pathology (e.g., acoustic neuroma, unilateral trauma).

Note: Diagnostic findings should always be interpreted by a qualified healthcare professional together with the patient’s symptoms, medical history, physical examination, laboratory investigations, previous imaging studies, and other relevant clinical information. Additional investigations or specialist consultation may be recommended depending on the findings.

Why Choose Chughtai Lab for Pure Tone Audiometry & Tympanometry?

• Experienced Healthcare Professionals: Assessments are conducted by highly qualified audiologists and trained technicians specializing in occupational health.
• Patient-Focused Care: Personalized attention is given to every patient, ensuring comfort, clear instructions, and a stress-free testing experience.
• Quality Diagnostic Services: Chughtai Lab maintains rigorous quality control standards across all diagnostic modalities, ensuring highly accurate and reproducible clinical data.
• Professional Reporting: Comprehensive, easy-to-read reports featuring detailed audiograms and tympanograms with professional clinical interpretations.
• Modern Diagnostic Approach: Utilizing state-of-the-art, regularly calibrated audiometers and tympanometers inside certified soundproof testing booths.
• Comfortable Environment: Modern, clean, and quiet clinical facilities designed to provide patients with a professional and reassuring diagnostic experience.
• Convenient Location: With an extensive nationwide network of diagnostic centers across Pakistan, accessing professional healthcare services is highly convenient.
• Commitment to Accurate Diagnosis: Dedicated to delivering precise, evidence-based diagnostic insights that support effective clinical decisions and corporate health compliance.