Did COVID-19 kill the sound booth?

(an opinion piece)

AIRFLOW, AIRFLOW, AIRFLOW! Make sure you have proper airflow in your office and in your sound booth. Make sure the AC in your consultation room does not recirculate air, as this will increase the risk of cross-contamination. If your aircon recirculates air, shut it off now. Open the windows of your consultation room and leave them open. Yeah, I know the cold is sometimes a problem and that many windows cannot open, but then make another plan. Your health, as well as the health of your staff and patients, are at stake here.

As a medical doctor, I have been involved with large roll-outs of MDR-TB diagnostic audiological points of presence in South Africa, Botswana, Indonesia and many other countries, and learned a lot when it comes to audiology and cross-contamination. There are many similarities between the monitoring of ototoxicity in MDR-TB and delivering audiology services in the age of COVID-19. In both cases, one has to continue delivering services in spite of the high risk of cross-contamination in a sound booth. I saw many approaches to the monitoring of MDR-TB ototoxicity throughout the world. Listed below, the first four options are not acceptable according to me. Unfortunately, I see the same failed logic being applied during the COVID-19 pandemic:

• No monitoring of aminoglycoside ototoxicity in MDR-TB in fear of cross-contamination. “Deaf or death“. The same is happening in COVID-19. Some recommendations are not to test new patients except in an emergency. What defines an emergency? Is not being able to hear other people or the COVID-19 news on TV an emergency? According to me, it is.
• Monitoring of ototoxicity in sound booths with traditional headsets, but not waiting long enough between patients to allow for full air exchange.
• Monitoring of ototoxicity outside sound booths with traditional headsets that cannot block ambient noise effectively.
• Test all MDR-TB patients at the end of the day. This is still a risk because you will never know that a so-called non-infective patient was tested in the booth just before a 78-year-old man with diabetes got tested. Additionally, there are different strains of MDR-TB, and you do not want a more resistant strain to infect another MDR-TB patient.
• Monitoring of ototoxicity outside a sound booth with boothless headsets, designed to test accurately outside a sound booth in the open air, Is the only acceptable, safe and accurate option.

The risk and fear of contracting MDR-TB is usually the motivation by healthcare professionals to not monitor ototoxicity properly. The rule of thumb in South Africa is that you have to leave the door of an unventilated sound booth open for 15 minutes between patients. How this value is determined is unknown and the scientific foundation of this value is in doubt. The time to wait is probably more towards 30 minutes for a small sound booth. The other practice is to only test the patients with MDR-TB at the end of the day after the booth was used throughout the day for diagnostic testing of non-infected patients. This allows more than 12 hours for air exchange to happen with the door open. How can you be 100% sure a patient is not infectious in COVID-19? The risk of cross-contamination is understandable, but there is no reason to reduce the quality of care if there are solutions available in the world like audiometers with headsets designed to do quality boothless diagnostic hearing tests. Open-air diagnostic testing to monitor for ototoxicity in MDR-TB patients on ototoxic therapy is possible. Open-air diagnostic testing in COVID-19 is also possible.

Sound-booth as a viable option

Yes, you can still continue to use a booth. Certain rules, however, do apply:

1. Allow enough time for full booth air exchange between patients (Limits air transmission)
2. Sterilise the booth after full air exchange before the next patient enters (Limits fomite transmission)
3. Patients must wear the correct masks, that cover both the nose and mouth (Limits air transmission)
4. Patients must sterilise their hands before they enter the booth and are not allowed to touch their clothes or faces while they are in the booth (Limits fomite transmission)
5. Test known infective patients at the end of the day. (This is something we can never know. Infected patients might be asymptomatic.)

Allow enough time after the last patient before the next patient enters the booth:

• HVAC is connected to the sound booth: If your sound booth is connected to the HVAC (Heating, Ventilation, and Air Conditioning) system of the building then leave the door of a large sound booth closed for 15 minutes between patients to allow for full air exchange. A small screening sound booth might only need 2 minutes (AAA). It is important to get your HVAC agent to calculate the time for full air exchange and put it in writing for you.
• No Fan or HVAC is installed in your booth: We all know that non-ventilated sound booths can become uncomfortably “stuffy” and warm in a very short period of time after the door is closed. It is obvious that an unventilated sound booth is a “breeding ground” for SARS-CoV-2. A literature search on the air exchange time with open sound booth doors for unventilated sound booths delivered no results. It is thus not possible to provide proper guidelines on how much time to allow for full air exchange. Turbulence and poor ventilation areas in the booth must also be taken into account when calculating the air exchange time. It is thus not recommended to use a sound booth without a fan or HVAC, unless a specialist in air exchange can supply you with information on the time to leave the door open for full air exchange.
• Fan is installed in your booth: A fan is typically used to allow for air exchange in the booth to decrease the stuffiness due to exhaled humid air and to decrease the heat generated by the human body. The problem with fans is that they typically blow air into the consultation room and thus they will increase the risk of spreading viruses and bacteria through aerosols micro-droplets. It is of utmost importance that the fan extraction flows outside your rooms, or to install a HEPA filter or UVC air sterilising unit if the air is blown into the consultation room. A certified agent must certify the filtration to be sufficient and must provide evidence of the full air exchange rate. Without this evidence, a sound booth with an installed fan cannot be used for hearing tests during COVID-19. You will never know if the patient being tested is infectious.
• UV-C installed in the booth: Ultra-Violet C lights placed strategically to light up all areas of the sound booth is a very good alternative to sterilise sound booths. Thanks to the enclosed space no UV-C light can escape the booth between patients and the risk of eye damage is limited. I am talking here about direct light where the photons hit the equipment and walls and chair in the booth directly. Your UV-C specialist can give you a certificate of how long the lights should be on between patients to sterilise the room. Sterilisation can happen as quickly as 15 minutes with strong UV-C lights installed. The benefit of UV-C lights is that you do not need to wipe down the equipment between patients. Unfortunately, there is no literature available on the efficiency of UV-C sterilisation of sound booths. (Please note that a small fan-like UV-C  air steriliser installed on the roof does not sterilise the equipment, the walls and chair of the booth. These fan-like sterilisers will sterilise the air in the booth over a period of time. Make sure you keep to the certified time period for full air sterilisation and that you still sterilise the equipment and surfaces after air sterilisation).

Limit fomite transmission inside a booth:

• SARS-CoV-2, the virus responsible for COVID-19, can be detected on varying surfaces up to 72 hours. The virus can be detected on copper for up to 4 hours, and up to 72 hours on plastic and stainless steel. There are various materials that make up equipment in the sound booth (including the sound booth itself). Most sound-booth related materials are made up of plastic, such as cables, headset, and response button – thus fomite transmission is a possibility. 
• “All surfaces and equipment in the booth that the audiologist or patient come in contact with should be wiped down with a disinfectant similar to cleaning used in treatment rooms. This includes wiping the surfaces and equipment in the audiologist test area of the booth as well.” (AAA).
• As mentioned earlier, UV-C light can be used to sterilise the surfaces inside the sound booth.

It is inevitable that you will have to make changes to your sound booth to decrease cross-contamination. Do not forget to consider going boothless as an option. Consider creating multiple points of tele-practice services in your own country and in underserved countries so that you can reach more people in need.

A sound booth is not a viable option

The following recommendations are being followed by some audiologists and occupational health care practitioners. The primary concern is airborne particles that remain in the booth:

• Some institutions recommend moving your audiometer out of the booth and test patients in the consultation room during the acute phase of COVID-19. This practice is an inferior service because the room is typically not quiet enough to perform adequate diagnostic or screening audiology services. Rather use equipment that is certified to be used outside a sound booth.
• Certain institutions recommend not to do any new hearing tests unless it is an emergency. How can this practice be acceptable or deemed an adequate service if there are other options available? A person with some degree of hearing loss is dependent on lipreading for effective communication. During this time of COVID-19, many people with different levels of hearing loss are in urgent need of hearing care services, because wearing a facemask hides the mouth and facial expressions of the person communicating with them. This renders lipreading impossible
• Some institutions recommend the use of the KUDUwave or other boothless audiometers that can do a full battery of diagnostic tests, allowing you as an ethical healthcare professional to deliver adequate quality services to your patients.
• Sadly some scientists recommend lowering the standards of audiology care, and to not perform bone conduction or tympanometry. After all, middle ear pathology did not disappear with the arrival of the COVID-19 virus.

Will the sound booth survive?

Why would you move back into the booth, if quality diagnostic audiological services outside a sound booth are possible with the right equipment?

CDC (Centers for Disease Control and Prevention) states that audiological services are a medium to high risk for COVID-19 cross-infections because of the test setup, the duration of the appointments and due to the proximity. Extra vigilance is essential since a large number of people treated in audiology practices are of a high age, resulting in a  significantly higher mortality rate from contracting COVID-19. Since the sound booth, and in fact, your practice, are high-risk areas, why not consider drive-through, home-based and hospital bedside testing. With the correct equipment, quality, boothless, diagnostic tests can be reliably conducted. Large MDR-TB ototoxicity audiology roll-outs across the world are already boothless. Boothless diagnostic audiometers like the KUDUwave have been in the market since 2008.

In occupational/industrial health care it does not make sense to stay in the booth. Booths are usually unventilated, small and prone to fomite transmission due to the increased risk of touching contaminated surfaces. A full exchange of air can occur in 15 minutes in an unventilated sound booth with the door open. All the booth surfaces and equipment then need to be first sterilized before the next patient can be tested. This means that you can see a maximum of 3 patients an hour per booth. This limitation has been an issue with MDR-TB ototoxicity screening for decades. Unfortunately, this risk was ignored for a range of reasons. Employees would typically be pushed through unsterilised sound booths in the mines and at factories in South Africa where TB has a high incidence rate within the workforce. 1 in every 100 people in South Africa will contract TB annually. Unfortunately, the unscientific “15-minute full air exchange time” between patients is probably wrong. The time period is in all probability much longer. With the COVID-19 virus, the virus can remain active for up to 72 hours on some surfaces.

Offer boothless Drive-through or Home-based services: AAA suggests drive-through services to deliver device support services. With the KUDUwave you can perform diagnostic hearing test services as a drive-through service. This is due to the superior attenuation abilities of the KUDUwave that allows booth-free testing. This is further validated by built-in real-time SLM (Sound Level Meter) that monitors ambient environmental noise. A patient can place the KUDUwave on their own head, close the window of their car leaving the USB cables running through the window. The tests can then be performed on a laptop or tablet from outside the vehicle. This process allows you to perform diagnostic air, bone, speech and impedance audiometry with reflexes, with a single device.

“There is no excuse for performing inferior diagnostic services due to the risk of contracting COVID-19 if there is a KUDUwave available.”

Do not forget about boothless tele-audiology. A trained facilitator can travel to a patient’s home and facilitate the correct fitment of the insert ear tipsl and placement of the KUDUwave. Real-time (synchronous) teleaudiology testing can now be performed. Whether a patient is tested using a KUDUwave in a car, at home or inside a sound booth using traditional headsets plugged into an audiometer, the type of testing remains the same. You can see the patient via video conferencing, you can talk to the patient using the KUDUwave talk-forward feature, and you have full control over the audiometer. The truly great feature of the KUDUwave is that once it is in position on the patient’s head, there is no need to swap probes or move bone conductors. A video otoscope may also be connected via the KUDUwave software to capture images of the eardrum and ear canal. Low-touch audiology does not mean inferior audiology.

Boothless home-based tele-audiology testing. You can either have a facilitator go out to the home of a patient with the KUDUwave or you can ship a KUDUwave telemedicine-ready kit to the patient. Quality tele-audiology air, bone, speech, tympanometry and reflex testing can then be performed. Yes, there are mobile phone and tablet solutions now also promoting the same, but why should you skip bone and speech and even tympanometry testing if it usually forms part of your test battery? What changed?

Boothless tele-audiology services in the USA: The American Speech-Language-Hearing Association (ASHA) lists the guidelines for each state around teleaudiology. Tele-practice makes a lot of sense if your facilitator can travel to the patient for testing. The benefit again is that you can escape the sound booth if you have the right equipment for booth-less testing. ADA (Academy of Doctor of Audiology) specifies that procedures which one may be able to be provided via telehealth if telehealth provided by an audiologist is allowed by state licensure.

Boothless tele-audiology services in South Africa: Amidst the COVID-19 disaster, the HPCSA issued an amended telemedicine guideline on the 3rd of April 2020. The HPCSA had previously banned all forms of telemedicine where there was not a previously established practitioner-patient relationship. The Council then relaxed the restrictions to allow telemedicine for the duration of the coronavirus outbreak, and amended this restriction as follows: “Telehealth should preferably be practised in circumstances where there is an already established practitioner-patient relationship. Where such a relationship does not exist, practitioners may still consult using telehealth, provided that such consultations are done in the best clinical interest of patients”. It is also important to note that “Practitioners may charge a fee for services rendered through a telehealth platform”. With this change, South Africans can now embrace solutions that effectively deliver healthcare services to remote and underserved areas. It is our responsibility as healthcare practitioners to expand our reach and to deliver essential services to the poor and frail in underserved areas?

“As an audiologist, I see no reason to move back into the booth. COVID-19 taught me that quality testing is possible outside the sound booth with the KUDUwave.”

A scary trend

The scary trend that is currently being promoted is to lower the standards of audiology care so that mobile phones and tablets can screen employees outside a sound booth and can be used to fit hearing aids outside a sound booth. Is it okay to lower the standards? What is this trend?

Standard transducers without Ambi-dome functionality like the KUDUwave typically do not attenuate noise well enough for diagnostic and even screening testing. What is the difference between a normal audiometer with a supra-aural headset and a mobile phone or tablet with a supra-aural headset? Both attenuates the noise equally poor. For the past 6 decades, it was scientifically obvious that these headsets need to be used inside a sound booth. Now suddenly, it is promoted to use these same headsets outside a booth when plugged into a mobile phone or tablet. What changed? Monitoring of the ambient noise by the mobile phone microphones? The only real thing that changed is that apps now do the same testing as audiometers used to do. Why not use a 30-year-old traditional audiometer to do boothless testing. No, you will not do that because the headset must be inside a sound booth. Now, why may the same headset be used outside a sound booth if now plugged into a tablet or phone?

The current trend to promote the lowering of standards and to sneak apps into testing the hearing of patients is, in my opinion, not how an audiologist prevents the lowering of standards of professional conduct. If there were no headset audiometer devices in the world that could test patients accurately outside a sound booth, then maybe there is a place for apps to test patients during COVID-19, but these devices do exist and have been in use for over 10 years.

“It is time to escape the sound booth. Think outside the box. But beware that you do not lower your standards.”

Never in the history of mankind was it acceptable to decrease the quality of healthcare to promote other avenues of delivering inferior services for the sake of selling a hearing aid? I cannot believe what I read and hear on webinars on a regular basis. The standards of professional audiology services can never be lowered for the sake of COVID-19. Solve the problem, do not lower your standards. Lowering the standards is a sure bullet for audiology practice. That is why I developed the KUDUwave so that audiologists can take control of the future of audiology care and be in charge of delivering quality audiology services to even more patients. COVID-19 might be the watershed to deliver boothless in-person service, to deliver boothless tele-audiology services and to deliver booth-free home-based services.

Please feel free to send your confidential comments, opinions and suggestions to dirk@emoyo.net. I would love hearing from you.