PONE-D-20-05119

LoCHAid: An ultralow-cost hearing aid for age related hearing loss

PLOS ONE

Dear Dr. Bhamla,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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We look forward to receiving your revised manuscript.

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Pedro de Lemos Menezes, Ph.D

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This interesting m/s describes a proof-of-concept project -- the development of an "ultralow-cost" hearing aid, particularly developed for individuals living in resource-challenged regions. The authors convincingly show that it is possible to construct, using off-the-shelf components, a very low cost device that can provide basic amplification for adults with a wide variety of hearing loss configurations. The paper is of interest not only because of the affordable nature of potential devices built using this strategy but also because the authors point out some of the barriers to widespread take-up of such a device. I feel that, with some minor revisions, the m/s would be of value to the audiological scientific community.

There are a number of points where the authors should consider revisions. These are:

The Abstract claims the h/aid "costs only 98 cents (< $1) to mass manufacturer". However, the text states that mass manufacture would indeed cost substantially more than this. The authors should take care not to "over-sell" their proof-of-concept device in the Abstract. The first sentence is rather odd and should be altered -- do the authors mean that hearing aids are the primary tool in non-medical rehabilitation for persons with hearing loss? The "audiological market" as is written is a very vague and wide term and should be avoided. Consumer Technology Association for Hearing Aids. I don't understand why Hearing Aids is capitalized.

Introduction

p.2 Hearing aids are the "most frequently used" what in rehabilitation? Something missing. Same for "public policy" .. public policy what?

"..have been reported ... charateristics and .." is redundant and can be deleted.

p. 3 "supported" seems wrong in this context ... advocated would be more appropriate. line 70 .. both coupler and real-ear simulator measures were conducted through a Verifit Speechmap hearing aid analyzer. Or was another device used to measure the h/aid output from the KEMAR manikin? This sentence needs correction.

p. 4 better if "requires few soldering points"

p. 5 line 143 The THD statement is misleading. WHO only allows 8% at certain low frequencies, not as an overall figure. This statement needs correction.

p. 7 "strength 65 dB SPL" is rather unscientific. Better if "an ISTS signal of 65 dB SPL was played".

p. 9 To avoid over-generalization besterr to state "which often do not exist in LMIC". Line 259 Why the "($140)" in the text? Seems not reason for this to appear.

p. 10 should be "mass manufacturer" [singular not plural].

p. 11 line 317 better if "a lower EIN for the device".

References

Ref 3 should be "Beaver Dam"

Ref 4 should be Journal of Neuroscience - delete "The" and "the official..."

Ref 5 has no journal pages numbers

Ref 15 National Academies of Sciences, Engineering, and Medicine should be capitalized.

Ref 20 World Health Organization is duplicated.

Ref 36 "McPherson" is incorrectly spelled.

Ref 37 No publication etc. details are provided.

Ref 38 No publication etc. details are provided.

Figures 3 and 4b are almost impossible to read. I suggest creating multiple figures, one for male data, one for female data and one for hearing profile X, Y, Z data.

Table II legend Need to write "PPP" in full

Throughout the m/s there were times when my PDF file showed missing spaces between letters, such as page 2, line 43 "... (e.g.,lack of...". Check the m/s thoroughly for such typos.

Reviewer #2: - Reposition the METHODS section, which should be after the introduction;

- The video mentioned in line 98 (Video 4) should show the impact of LoCHAid from different perspectives;

- Line 116: I suggest a sub-topic on the cost of the device;

- Line 289: About the smaller prototype, I suggest a figure that shows the final device.

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Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

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PONE-D-20-05119R1

LoCHAid: An ultralow-cost hearing aid for age related hearing loss

PLOS ONE

Dear Dr. Bhamla,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Sep 25 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

Pedro de Lemos Menezes, Ph.D

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: N/A

Reviewer #2: (No Response)

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: (No Response)

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The revised m/s meets almost all my initial review comments and now has improved readability and focus. The m/s covers an area that is under-researched and I commend the research team for their exploratory work.

My remaining comments concern minor points. Attention to these would further improve the final m/s:

page 4/16 better if just "... with the manikin inside."; inconsistent use of units in the paper - here and in S4 Video legend feet are used rather than metric units. Metric units should be used at all times throughout the paper.

page 5/16 mentions an estimated device lifespan of only 1.5 years. This issue should also be very briefly considered in the discussion.

Table 2, page 7/16. change "HZ" to "Hz" as in all other instances in the table.

page 10/16 makes the claim that the low cost device can be used in "screening for potential hearing loss". This is a puzzling statement because nowhere in the m/s is a device screening function mentioned. I think this goes well beyond the scope of the present research paper and should be deleted.

Some references still have problems: #4 should be just "The Journal of Neuroscience"; #15 and #19 just "JAMA"; #23, #24, #26, #27 and #34 are all incorrectly titled and need revision. #43 there should be no space before "?"

Reviewer #2: (No Response)

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

LoCHAid: An ultralow-cost hearing aid for age related hearing loss

PONE-D-20-05119R2

Dear Dr. Bhamla,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Pedro de Lemos Menezes, Ph.D

Academic Editor

PLOS ONE