PTA at Dr. Essa Lab

PTA at Dr. Essa Lab

Pure Tone Audiometry, commonly abbreviated as PTA, is the foundational and gold-standard subjective behavioral test used to evaluate hearing sensitivity and determine the threshold of hearing in individuals. At Dr. Essa Lab, a premier diagnostic institution in Karachi, Pakistan, this advanced audiological assessment is conducted under highly controlled clinical conditions. The primary objective of a PTA test is to identify the quietest sounds a patient can hear at different frequencies, ranging from low pitches to high pitches. By mapping these thresholds, the test provides a comprehensive overview of an individual’s auditory health, helping clinicians differentiate between various types and degrees of hearing impairment.

The auditory system is a complex network comprising the outer ear, middle ear, inner ear, and the vestibulocochlear nerve (cranial nerve VIII), which transmits electrical signals to the temporal lobe of the brain. The PTA test works by assessing two distinct pathways of hearing: air conduction and bone conduction. Air conduction testing evaluates the entire auditory pathway, from the pinna and external auditory canal, through the tympanic membrane and ossicular chain of the middle ear, to the cochlea and neural pathways. Bone conduction testing, on the other hand, utilizes a specialized bone vibrator placed on the mastoid process of the temporal bone. This device bypasses the outer and middle ear, directly stimulating the cochlea via bone vibrations. Comparing the results of these two pathways allows audiologists to pinpoint the exact anatomical site of any hearing pathology.

At Dr. Essa Lab, the PTA procedure is performed using state-of-the-art, calibrated diagnostic audiometers inside a specialized, soundproof audiometric booth. This controlled environment is critical because even minor ambient noise can artificially elevate a patient’s hearing thresholds, leading to inaccurate diagnostic results. The clinical value of PTA is immense; it serves as the primary diagnostic tool for evaluating patients presenting with hearing loss, tinnitus, speech comprehension difficulties, or balance disorders. It is also essential for pre-employment screenings in noise-hazardous industries, monitoring patients on ototoxic medications, and evaluating candidates for hearing aids or middle ear surgeries.

Clinical Procedure: What to Expect

Patient Preparation

Proper patient preparation is essential to ensure the clinical accuracy and reliability of a PTA test. Patients scheduled for a PTA at Dr. Essa Lab should adhere to the following guidelines:

• Avoid Loud Noise Exposure: Patients must avoid exposure to extremely loud environments, such as concerts, industrial factories, firearms, or loud music, for at least 16 hours prior to the test. This prevents a physiological phenomenon known as temporary threshold shift (TTS), which can temporarily compromise hearing sensitivity and skew test results.
• Otoscopic Examination: Before commencing the PTA, a qualified clinician or audiologist at Dr. Essa Lab will perform an otoscopic examination of the external auditory canal. This is done to ensure the ear canal is free of impacted cerumen (earwax), foreign bodies, or signs of active infection (such as otitis externa), which could obstruct sound waves and cause an artificial conductive hearing loss.
• Remove Interfacing Accessories: Patients will be asked to remove any items that could interfere with the proper placement and seal of the headphones or bone conduction oscillator. This includes eyeglasses, large earrings, headbands, hairpins, and hearing aids.
• Communication and Cooperation: Because PTA is a subjective behavioral test, it requires the patient’s active participation and concentration. Patients should be well-rested. There are no dietary restrictions or fasting requirements; patients may eat, drink, and take their routine medications normally.

During the Procedure

The clinical execution of a PTA test at Dr. Essa Lab follows a standardized, systematic protocol to ensure maximum diagnostic precision:

• Patient Positioning: The patient is comfortably seated inside the soundproof audiometric cabin. The audiologist positions themselves outside the booth, maintaining visual contact with the patient through a double-paned observation window.
• Headphone Placement: For the air conduction phase, the audiologist places calibrated over-ear headphones (or insert earphones) over the patient’s ears. Red-coded headphones are placed on the right ear, and blue-coded headphones are placed on the left ear.
• Instruction Delivery: The audiologist instructs the patient to respond immediately whenever they hear a tone, no matter how faint or distant it may seem. Responses can be made by pressing a hand-held response button, raising a hand, or giving a verbal indication.
• Tone Presentation: The audiologist presents pure tones at specific frequencies, typically starting at 1000 Hz, which is the frequency most familiar to human hearing. The test then proceeds to higher frequencies (2000 Hz, 4000 Hz, 8000 Hz) and then to lower frequencies (500 Hz, 250 Hz). The intensity of the tones is adjusted using the modified Hughson-Westlake method (down 10 decibels, up 5 decibels) to find the exact threshold where the patient can detect the sound 50% of the time.
• Bone Conduction Testing: Once air conduction is complete, the headphones are removed, and a bone conduction oscillator is placed on the mastoid bone behind the ear. The same threshold-seeking procedure is repeated to evaluate the sensitivity of the inner ear directly.
• Duration and Safety: The entire procedure is completely non-invasive, painless, and carries zero risk of radiation or discomfort. It typically takes between 20 to 30 minutes to complete both ears.

When is a PTA Performed?

Age-Related Hearing Loss (Presbycusis)

As individuals age, progressive degenerative changes occur within the cochlea, particularly affecting the hair cells in the basal turn, which are responsible for detecting high-frequency sounds. This condition, known as presbycusis, typically manifests as a gradual, bilateral, and symmetrical hearing loss. Patients often complain of difficulty understanding speech in noisy environments, such as family gatherings or restaurants, and may report that others seem to be mumbling. Physicians request a PTA to objectively quantify the degree of hearing loss across different frequencies, allowing for the appropriate prescription of digital hearing aids and assistive listening devices to improve the patient’s quality of life.

Noise-Induced Hearing Loss (NIHL)

Prolonged or sudden exposure to high-intensity noise can cause mechanical and metabolic damage to the delicate outer hair cells within the organ of Corti. This is common in individuals working in construction, aviation, military, or manufacturing sectors, as well as those exposed to recreational loud noises. Symptoms include a muffled sensation in hearing and persistent high-pitched tinnitus. A PTA is highly diagnostic in these cases, typically revealing a classic notch-like hearing loss at 4000 Hz (4 kHz notch), which is pathognomonic for noise-induced damage. The test helps in monitoring occupational health, establishing baseline hearing, and implementing hearing conservation protocols.

Chronic Otitis Media and Middle Ear Pathology

Inflammatory conditions of the middle ear, such as chronic otitis media with effusion, tympanic membrane perforations, or otosclerosis (abnormal bone remodeling in the middle ear), impede the mechanical transmission of sound waves from the tympanic membrane to the oval window. Patients often present with ear pain, discharge, a feeling of fullness, and decreased hearing. A physician requests a PTA to assess the integrity of the middle ear conduction system. The test assists in diagnosing these conditions by demonstrating an “air-bone gap,” where bone conduction thresholds remain normal but air conduction thresholds are significantly elevated, guiding surgical or medical management.

Tinnitus and Unilateral Hearing Changes

Tinnitus, characterized by a ringing, buzzing, or roaring sound in one or both ears, is frequently a symptom of underlying auditory system pathology. When tinnitus is accompanied by sudden or unilateral hearing loss, it represents a clinical scenario that requires prompt investigation. This presentation can indicate conditions ranging from simple cerumen impaction to serious retrocochlear lesions, such as an acoustic neuroma (vestibular schwannoma). A PTA is immediately performed to determine if the hearing loss is sensorineural or conductive and to assess its symmetry, providing vital diagnostic data that determines whether advanced neuroimaging (such as an MRI of the internal auditory meatus) is warranted.

Ototoxicity Monitoring during Medical Treatments

Certain essential medical treatments involve medications that are known to be ototoxic, meaning they can cause permanent damage to the sensory cells of the inner ear. Common ototoxic agents include platinum-based chemotherapy drugs (such as cisplatin), aminoglycoside antibiotics (such as gentamicin), and loop diuretics. Patients undergoing these treatments may experience rapid-onset high-frequency hearing loss or vestibular dysfunction. Physicians request baseline and serial PTA tests during the course of treatment to detect early subclinical hearing loss in the ultra-high frequencies, allowing oncologists or infectious disease specialists to adjust drug dosages before irreversible damage occurs to conversational speech frequencies.

What Does a PTA Detect?

A PTA test is highly sensitive and capable of detecting a wide array of clinical conditions and hearing profiles. The primary diagnostic findings include:

• Normal hearing thresholds across all tested frequencies (0 to 20 dB HL).
• Mild conductive hearing loss (26 to 40 dB HL with an air-bone gap).
• Moderate conductive hearing loss (41 to 55 dB HL with an air-bone gap).
• Moderately-severe conductive hearing loss (56 to 70 dB HL).
• Severe conductive hearing loss (71 to 90 dB HL).
• Mild sensorineural hearing loss (no air-bone gap).
• Moderate sensorineural hearing loss.
• Moderately-severe sensorineural hearing loss.
• Severe sensorineural hearing loss.
• Profound sensorineural hearing loss (greater than 90 dB HL).
• Mixed hearing loss (both air and bone conduction thresholds are impaired, with an air-bone gap of greater than 10 dB).
• Bilateral symmetrical high-frequency sensorineural hearing loss (typical of presbycusis).
• Unilateral sensorineural hearing loss (suggestive of unilateral pathology).
• Noise-induced hearing loss characterized by a “notch” or drop at 4000 Hz (4 kHz notch).
• Low-frequency sensorineural hearing loss (often associated with early-stage Meniere’s disease).
• Flat configuration hearing loss (equal loss across all frequencies).
• Sloping configuration hearing loss (greater loss in higher frequencies).
• Rising configuration hearing loss (greater loss in lower frequencies).
• Cookie-bite configuration hearing loss (mid-frequency hearing loss, often congenital).
• Carhart’s notch (characteristic drop in bone conduction threshold at 2000 Hz, indicative of otosclerosis).
• Asymmetrical hearing loss (difference of 15 dB or more between ears at three consecutive frequencies).
• Left ear unilateral conductive hearing loss.
• Right ear unilateral conductive hearing loss.
• Preserved ultra-high frequency hearing thresholds.
• Complete anacusis (total deafness in the tested ear).

Turnaround Time and Report Access at Dr. Essa Lab

At Dr. Essa Lab, we understand that timely diagnostic results are crucial for effective clinical decision-making and patient peace of mind. Because PTA is an interactive, real-time behavioral test, the raw data is captured and plotted on an audiogram immediately during the procedure by our qualified audiologist. Following the completion of the test, the audiologist performs a detailed analysis of the air conduction and bone conduction thresholds, calculates the pure-tone average, and drafts a comprehensive clinical interpretation. This report is then verified and signed.

The finalized, professionally verified PTA report is typically available within a few hours on the same day of the test. Dr. Essa Lab provides multiple convenient options for accessing your diagnostic reports. Patients can securely view, download, and share their digital reports through the official Dr. Essa Lab online web portal or dedicated mobile application. For those who prefer physical copies, printed reports with high-quality graphical audiograms can be collected directly from the reception desk of the diagnostic center where the test was performed.

PTA Findings Overview

Structure / Parameter Evaluated	Normal Findings	Possible Abnormal Findings
Air Conduction Thresholds (Right Ear)	0 to 20 dB HL across all tested frequencies (250 Hz – 8000 Hz)	Thresholds greater than 20 dB HL, indicating potential hearing impairment.
Air Conduction Thresholds (Left Ear)	0 to 20 dB HL across all tested frequencies (250 Hz – 8000 Hz)	Thresholds greater than 20 dB HL, indicating potential hearing impairment.
Bone Conduction Thresholds (Right Ear)	0 to 20 dB HL; matches air conduction thresholds within 10 dB	Thresholds greater than 20 dB HL, indicating sensorineural or mixed hearing loss.
Bone Conduction Thresholds (Left Ear)	0 to 20 dB HL; matches air conduction thresholds within 10 dB	Thresholds greater than 20 dB HL, indicating sensorineural or mixed hearing loss.
Air-Bone Gap (ABG)	Less than or equal to 10 dB HL difference between air and bone conduction	ABG greater than 10 dB HL, indicating conductive or mixed hearing loss.
High-Frequency Sensitivity (4000 Hz – 8000 Hz)	Thresholds within normal limits (0 to 20 dB HL)	Significant drop (notch or slope), indicating noise-induced damage or presbycusis.
Low-Frequency Sensitivity (250 Hz – 500 Hz)	Thresholds within normal limits (0 to 20 dB HL)	Elevated thresholds, indicating conductive issues or conditions like Meniere’s disease.
Bilateral Symmetry	Symmetrical thresholds between both ears (difference less than 15 dB)	Asymmetric thresholds, suggesting unilateral pathology requiring further imaging.

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 Dr. Essa Lab for PTA?

• Experienced healthcare professionals and certified audiologists who ensure accurate testing and precise audiogram plotting.
• Patient-focused care that prioritizes comfort, clear instructions, and a stress-free diagnostic experience.
• Quality diagnostic services backed by decades of trust and reliability in Pakistan’s healthcare landscape.
• Professional reporting with detailed interpretations of air and bone conduction thresholds to assist your ENT specialist.
• Modern diagnostic approach utilizing calibrated audiometers and standardized soundproof audiometric booths.
• Comfortable environment designed to minimize external noise interference and ensure patient relaxation during the test.
• Convenient locations across Karachi and other major cities, making diagnostic services highly accessible.
• Commitment to accurate diagnosis, adhering to international standards of audiological assessment and quality control.