UPDATE: Council for Accreditation in Occupational Hearing Conservation

Letter to the Editor

Dear Editor,

We are writing to outline concerns we have with the article published in the CAOHC UPDATE Newsletter Volume 31, Issue 2 entitled The Future of Hearing Conservation. The article contains the following inaccuracies about tablet audiometers and, as the only vendor cited in the article, about our product, SHOEBOX Audiometry, specifically.

1. Medical Device:  The article questions whether tablets can be operated as medical devices. SHOEBOX Audiometry is a clinically validated, Class 2 medical device registered with Health Canada, the FDA, and the European Union. In accordance with medical device regulations, the Company is audited annually by an independent third party for ISO13485 compliance. SHOEBOX Audiometry meets the criteria of a Type 3 audiometer defined by ANSI/ASA S3.6-2018 Specification for Audiometers and surpasses the requirements for an audiometer used for occupational hearing testing, which is a Type 4.

2. Validation Studies: The information presented on the clinical validation, sensitivity, and specificity in the article is not accurate; It references a sensitivity of 86.5% from the study by Saliba et al. (2017). That validation study found that SHOEBOX Audiometry demonstrated a sensitivity of 100%.

The article also cites studies of SHOEBOX Audiometry being used in specific clinical settings and incorrectly applies them to occupational testing. It references results from a study that was used to determine the accuracy of SHOEBOX Audiometry, but fails to note that the study tested threshold accuracy in artificially noisy conditions for comparison purposes. These conditions significantly surpassed OSHA pre-defined maximum permissible ambient noise levels (MPANLs) and are therefore not representative of acceptable occupational testing environments.

3. Tablet Models: The article references a Reddit article that suggests hardware and software updates of tablet-based systems create inaccuracies. This suggestion is false. SHOEBOX exhaustively tests each model of iPad used, as well as all operating system updates, to ensure accuracy of our systems prior to commercial release. In five years of operation, no iPad has become incompatible with our software.

4.  Damage to iPads: The article suggests that handling the iPad during operation could cause damage. The risk is extremely low. Each system ships with a stand so users do not hold the iPad during testing. Equipment regularly shipped across the country in the back of a mobile testing unit is more likely to be damaged.

5.  Calibration: The article questions whether iPad audiometers can be properly calibrated in accordance with OSHA requirements. All SHOEBOX audiometers are fully calibrated for compliance with ANSI/ASA S3.6-2018 in our laboratory prior to delivery. They are exhaustively recalibrated annually - exceeding the requirement for an exhaustive calibration only every two years. 

Thank you for the opportunity to clear up these inaccuracies.

Michael Weider

If you have any questions, please contact SHOEBOX directly.

CAOHC hereby confirms that the opinions expressed in this letter to the editor and the article to which it refers are those of the authors and do not necessarily reflect official CAOHC policy or the views of CAOHC. CAOHC does not officially take any position in support or endorsement of either the letter to the editor or the associated article. CAOHC recommends that the reader consult applicable federal, state and local laws and regulations, as well as any other applicable policies, procedures, and regulations pertaining to audiometric equipment standards, testing environment, and calibration requirements with reference to the reader's situation.