Dear Editor:

We read with interest the article titled “PSAPs vs Hearing Aids: An Electroacoustic Analysis of Performance and Fitting Capabilities” by Chase Smith, AuD,  Laura Wilber, PhD, and Kim Cavitt, AuD (July 2016 Hearing Review).1  We felt the article contained some glaring omissions that could mislead the reader:

  1. Figure 3 in Smith et al shows average Total Harmonic Distortion (THD) from highest to lowest (in %). Dr Cherukuri questions the methodology and appropriateness of the testing an the MDHearingAid device (an AGC hearing aid) vs a linear or digital hearing device.

    Figure 3 in Smith et al shows average Total Harmonic Distortion (THD) from highest to lowest (in %). Dr Cherukuri questions the methodology and appropriateness of the testing and comparison of the MDHearingAid device (an AGC hearing aid) versus a linear or digital hearing device.

    The MDHearingAid PRO, to our knowledge, is the lowest priced FDA registered hearing aid in the United States.  As such, it is an analog hearing aid, the fact of which is omitted in the article.  As you know, analog hearing aids by design will have higher total harmonic distortion (THD) than digital hearing aids, but the THD of the MDHearingAid PRO is consistent with a high quality analog hearing aid (and within the ANSI standard). What is also omitted is the testing methodology for THD for the PRO. If it was tested as an AGC aid instead of a linear aid, the harmonic distortion values will be misrepresented.

  2. Since the high-end PSAPs tested in the study cost up to $349, a more appropriate comparison hearing aid would be the MDHearingAid AIR, which is one of the lowest-price digital hearing aids in the United States ($349).  The AIR features the acoustic processing strategies you highlight, such as wide dynamic range compression and feedback suppression. Our MDHearingAid VOLT further adds directional microphone and rechargeability for $549/aid.
  3. It is not clear how pre-programmed hearing aids are handled in your study. The MDHearingAid PRO has 2 pre-programmed settings that accommodate the most common configurations of hearing loss (flat and high-frequency), as well as volume adjustments that allow for the user to fine-tune the output to their needs.  Were adjustments made based on the audiometric profile you were trying to fit to? If this was not done, then it would skew the results regarding appropriate fit. Our data (and thousands of satisfied users) show that the PRO would be appropriate for 6 or 7 of the profiles highlighted in the study.  In fact, the PRO is the only direct-to-consumer hearing aid that has been the subject of IRB-approved research and presented at the American Academy of Otolaryngology-Head and Neck Surgery Annual Meeting.
  4. Can you please clarify why the authors chose to borrow the SoundHawk device while it appears that all other devices were purchased?  This introduces an element of conflict of interest to the study.  In fact, when SoundHawk was the only PSAP that scored high in a specific category, it was called out by name.  However, when other PSAPs were exclusive high-performers, they were only vaguely referenced or incorrectly omitted. When the SoundHawk performed poorly in a particular category (EIN), a rationalizing paragraph was included. The readers should also know that SoundHawk is no longer available for sale.

In conclusion, while your article discusses low-cost hearing solutions for the millions of Americans that cannot afford traditional hearing aids, there are certain omissions that may mislead the reader. With over 200,000 satisfied users, MDHearingAid is able to conclude that low-cost FDA-registered hearing aids are providing a valuable alternative to high-priced aids.

—Sreekant Cherukuri, MD (Board Certified Otolaryngologist), Founder, MDHearingAid Inc

Response from Dr Smith:

Dear Dr Cherukuri:

Thank you for your thoughts and additional information on your products.

The purpose of this study was two-fold: to provide electroacoustic data on these products, given that many of these products do not have this information available to hearing healthcare providers, and to determine if these products could effectively match established real-ear targets and remediate hearing loss. Devices were adjusted and/or programmed as they would be by the consumer. We stand by the data as presented and feel as though it accurately represents the objective function of the devices.

Also, as this study was self-funded, whether the device was loaned or purchased has no bearing on the data. There were no conflicts of interest present. Academic integrity is extremely important to our institution, and this study and any suggestion of bias, is unfounded.

The important point is that both consumers and hearing healthcare providers now have access to many amplification solutions and both need to have access to objective data on the performance and function of the products available. We encourage manufacturers of any product to make this type of data available.

— Chase Smith, AuD


1. Smith C, Wilber LA, Cavitt K. PSAPs vs hearing aids: An electroacoustic analysis ofperformance and fitting capabilities. Hearing Review. 2016;23(7)[July]:18-24. Available at: