DIGITAL LGOB PROCEDURE USING RESOUND, DIGITAL 5000 SERIES HEARING AIDS
Applicant
Resound Corp.
Product Code
EWO · Ear, Nose, Throat
Decision Date
Mar 19, 1999
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 874.1050
Device Class
Class 2
Indications for Use
The ReSound® Loudness Growth in Octave Bands (LGOB) Loudness Scaling System is a new indication for use for the ReSound Digital 5000 hearing device family. The control for the system is incorporated into ReSound ReSource II fitting application software. The testing procedure is intended to be performed only by qualified hearing healthcare professionals. The purpose of the ReSound LGOB test is to evaluate a patient's suprathreshold hearing at specific frequencies. This is the range of hearing above a person's threshold level but below their uncomfortable loudness level. The results of this test are used by the ReSource software to calculate hearing instrument fittings that are better tailored to the patient's residual dynamic range of hearing. The LGOB test procedure requires the patient to evaluate narrow bands of noise signals generated directly the Digital-to-Analog converter within the hearing device. The noise signal is Too Loud, Very Loud, Loud, Comfortable, Soft, Very Soft or Inaudible by entering their response with the hand held Personal Selector, which is the identical recording device used with the original P3 system from ReSound. The new LGOB application uses the patient's own digital hearing device or a stock "Digital Master" device to produce the sound stimulus directly from the Digital to Analog converter (DAC) within the hearing aid's Digital Signal Processor. No insert earphones are required. Either BTE or Custom In-The-Ear devices can be used to perform the LGOB loudness scaling measurements. The test protocol is initiated and controlled by connecting a Digital hearing device to a personal computer and using proprietary fitting software (ReSource II). When the fitting computer is disconnected, the hearing instrument functions normally. Results from the test are used to provide fitting recommendations and initial device amplification parameter settings for the Digital 5000 and other programmable ReSound hearing devices.
Device Story
System uses ReSound Digital 5000 series hearing devices to perform Loudness Growth in Octave Bands (LGOB) testing; replaces traditional insert earphones with direct sound generation via hearing aid's internal Digital-to-Analog Converter (DAC). Hearing professional connects device to PC running ReSource II software; software instructs DAC to produce 1/2 octave bands of noise at varying frequencies/amplitudes. Patient uses handheld 7-button Personal Selector to rate perceived loudness (Too Loud to Inaudible). Software collects/stores data; calculates target response curves/amplification settings based on LGOB and audiometric threshold data. Facilitates precise fitting of hearing aid to patient's residual dynamic range. Used in clinical settings by hearing health professionals; device functions as standard hearing aid when disconnected from PC.
Clinical Evidence
Bench testing only. System relies on established LGOB loudness scaling methodology (Allen et al., 1988/1990). No clinical trial data presented; equivalence established through technical comparison of stimulus generation and software-based fitting workflow.
Technological Characteristics
System comprises PC software and Digital 5000 series hearing aids. Hearing aids feature custom digital signal processor (DSP) with two ADCs and one DAC. Connectivity via standard CS45 cable to PC. Software-controlled stimulus generation. Complies with ANSI S3.6-1996, ANSI S1.6-1984, and ANSI S3.22-1996. Software developed per IEEE 1012-1986.
Indications for Use
Indicated for hearing-impaired patients requiring audiometric assessment of suprathreshold hearing to improve hearing aid fitting accuracy. Intended for use by qualified hearing healthcare professionals.
Regulatory Classification
Identification
An audiometer or automated audiometer is an electroacoustic device that produces controlled levels of test tones and signals intended for use in conducting diagnostic hearing evaluations and assisting in the diagnosis of possible otologic disorders.
Predicate Devices
ReSound® Portable Prescriptive Programming (P3) System (K912669)
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3/19/99
Image /page/0/Picture/1 description: The image shows the logo for ReSound Hearing Health Care. The word "RESOUND" is in large, bold, sans-serif font. Below it, the words "Hearing Health Care" are in a smaller, sans-serif font.
K984547
510(k) Premarket Notification - LGOB Using Digital Hearing Devices
### EXHIBIT E
## 510(k) Summary of Safety and Effectiveness
[As required by 807.92(c)]
Submitter:
ReSound Corporation 220 Saginaw Drive, Seaport Centre, Redwood City, CA 94063 Tel: 650 780-7800 Fax: 650 261-2284
Contact Person:
December 20, 1998 Date:
Common/Usual Name: Audiometer; Digital Master Hearing Aid
Gary Roesel
LGOB Test using ReSound® Digital 5000 Series Hearing Devices Proprietary Name:
Panel 77, Procode ESD Classification CFR Part 874 – Ear, Nose, and Throat Devices Diagnostic Devices - 874.1050 Audiometer Subpart B -Prosthetic Devices - 874.3330 Master Hearing Aid Subpart D --
Establishment Registration: 2939186
#### References and Performance Standards:
Applicable sections of ANSI S3.6 - 1996, "Specification for Audiometers."
Applicable sections of ANSI S1.6-1984 (R 1990), "Preferred Frequencies, Frequency Levels and Band Numbers for Acoustical Measurements."
Applicable sections of ANSI S3.22-1996, "Specification of Hearing Aid Characteristics."
Software development and validation according to IEEE 1012-1986 and the FDA Guidelines for Computer Controlled Medical Devices.
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J. B. Allen. J. L. Hall, and P. S. Jeng. "Loudness growth in 1/2-octave bands (LGOB) - A procedure for the assessment of loudness", Journal of the Acoustical Society of America - 1988 (2), 1990, pp. 745-753.
Using the Digital 5000 series of hearing devices to produce sound Substantial Equivalence: stimuli and perform LGOB loudness scaling measurements is substantially equivalent to other currently marketed audiometric diagnostic testing equipment, and is almost identical to that marketed as the ReSound® Portable Prescriptive Programming (P3) System (K912669).
ReSound's Digital 5000 series hearing devices are built using a custom Description: software programmable digital signal processor. The DSP includes two analog to digital converters (ADC) at the input stage and one digital to analog converter (DAC) at the output stage. Using a personal computer (PC) connected to the hearing device via standard CS45 cable, numerous signal processing and amplification parameters may be adjusted to help compensate for impaired hearing. In addition, proprietary software used only by hearing health care professionals can instruct the output DAC to produce specific sounds. These sound stimuli, when delivered at different amplitudes and frequencies, can be used for loudness scaling measurements helpful in fitting the hearing device more precisely to the patient's residual hearing dynamic range.
The "Loudness Growth in Octave Bands" (LGOB) loudness scaling test Intended Use: is intended to be used by hearing health care professionals as a supplemental audiometric measurement'. The LGOB test is intended to simplify and improve the accuracy of the fitting process for ReSound Digital or Analog hearing devices. Specifically, the test uses the Digital 5000 hearing device and proprietary software to directly produce 1/2 octave bands of noise presented at varying output levels and centered at varying frequencies. The hearing device wearer indicates their perceived loudness for each stimulus.
The new Loudness Growth in Octave Bands (LGOB) test application of Predicate Device: ReSound's Digital 5000 series hearing devices is substantially equivalent to the LGOB test developed by ReSound and provided with the original ReSound® P3 System cleared under 510(k) K912669, September 16, 1991. In the predicate device, the LGOB sound stimulus was generated by the Personal Prescriptive Programmer hardware and delivered via a set of insert earphones.
> The new LGOB application uses the patient's own digital hearing device or a stock "Digital Master" device to produce the sound stimulus
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directly from the Digital to Analog converter within the hearing aid's Digital Signal Processor. No insert earphones are required. Either BTE or Custom In The Ear devices can be used to perform the LGOB loudness scaling measurements. The test protocol is initiated and controlled by connecting a ReSound Corporation Digital hearing device to a personal computer and using proprietary fitting software (ReSound ReSource II). The patient's subjective loudness perception of each stimulus is recorded using the handheld Personal Selector, which is the identical recording device used with the original P3 system. When the fitting computer system is disconnected, the hearing instrument functions normally.
#### Summary:
The ReSound® Loudness Growth in Octave Bands (LGOB) Loudness Scaling System is a new indication for use for the ReSound Digital 5000 hearing device family. Using the Digital 5000 series of hearing devices to perform LGOB measurements is substantially equivalent to the LGOB procedure pioneered by ReSound and marketed with the ReSound Portable Prescriptive Programming (P3) System (K912669). The software which controls the system is incorporated into ReSound® ReSource II software (K945750) that runs as a standalone application or can be integrated under the Noah operating system (K942749).
The LGOB test equipment is comprised of proprietary PC software and a ReSound Digital 5000 series hearing device. Similar to the Loudness Growth in Octave Bands (LGOB) test provided with the original ReSound® P3 System, this new hearing device fitting method is designed to subjectively measure loudness growth in hearingimpaired subjects using the subject's own hearing aid, instead of using insert phones. The test is to be performed only by qualified hearing healthcare professionals. When the hearing aids are disconnected from the fitting computer, they function normally.
Substantial equivalence of this analysis system to currently marketed real ear systems mentioned above is based on the following:
- This system produces speech shaped noise stimuli delivered directly to the (1) patient's ear canal;
- (2) Measures the perceived intensity of the signals via a hand held 7-button Personal Selector, and;
- Displays the measurement results on the PC screen. (3)
<sup>4</sup> J. B. Allen, J. L. Hall, and P. S. Jeng, "Loudness growth in ½-octave bands (LGOB) - A procedure for the assessment of loudness", Journal of the Acoustical Society of America - 1988 (2), 1990, pp. 745-753.
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The new LGOB test procedure requires the patient to evaluate ½ octave bands of pseudo-random noise signals generated directly by the Digital-to-Analog Converter (DAC) within the Digital hearing device. The patient indicates if they perceive the noise signal to be: Too Loud, Very Loud, Loud, Comfortable, Soft, Very Soft or Inaudible by entering their response with the hand held Personal Selector.
The proprietary software collects, labels and stores the resulting loudness sensitivity data. The fitting target and subsequent hearing aid amplification settings for the Digital 5000 (or other programmable ReSound hearing devices) are derived from the LGOB suprathreshold data and supplied audiometric threshold data. Any and all settings for the device which are chosen by the software can be easily and directly changed by the hearing device fitting professional, as with all other ReSound digital or analog hearing aids.
The new ReSound LGOB incorporates the patient's subjective response data along with the patient's audiometric data (entered separately) in the calculation of target response curves for the fitting of ReSound hearing devices. The intended use, method and theory of test operation, fundamental testing protocol, application and calibration of test results are equivalent to the predicate ReSound P system.
The use of the ReSound® LGOB loudness scaling system with the Digital 5000 series hearing devices does not significantly affect the safety or effectiveness of the currently marketed ReSound Digital 5000 family of hearing devices or the currently marketed ReSound ReSource II fitting software.
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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
MAR 1 9 1999
Gary W. Roesel Director of Worldwide Technical Services, Regulatory Affairs ReSound Corporation 220 Saginaw Drive Seaport Centre Redwood City, CA
Re:
K984547 LGOB Test using ReSound™ Digital 5000 Series Hearing Devices Dated: December 20, 1998 Received: December 22, 1998 Regulatory class: II 21 CFR 874.1050/Procode: 77 EWO 21 CFR 874.3330/Procode: 77 KHL
Dear Mr. Roesel:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
If you desire specific advice for your labeling requlation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.qov/cdrh/dsma/dsmamain.html".
Sincerely yours,
BART Daniel S. Stulberg, M.D.
APT Daniel G. Schultz, M.D. Acting Director, Division of Reproductive, Abdominal, Ear, Nose and Throat. and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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510(k) Premarket Notification - LGOB Using Digital Hearing Devices
### EXHIBIT B
# INDICATION FOR USE STATEMENT
510(k) Number (if known):
ReSound LGOB Procedure using Digital 5000 series hearing devices Device Name:
Indications for Use:
The ReSound® Loudness Growth in Octave Bands (LGOB) Loudness Scaling System is a new indication for use for the ReSound Digital 5000 hearing device family. The control for the system is incorporated into ReSound ReSource II fitting application software. The testing procedure is intended to be performed only by qualified hearing healthcare professionals.
The purpose of the ReSound LGOB test is to evaluate a patient's suprathreshold hearing at specific frequencies. This is the range of hearing above a person's threshold level but below their uncomfortable loudness level. The results of this test are used by the ReSource software to calculate hearing instrument fittings that are better tailored to the patient's residual dynamic range of hearing. The LGOB test procedure requires the patient to evaluate narrow bands of noise signals generated directly the Digital-to-Analog converter within the hearing device. The noise signal is Too Loud, Very Loud, Loud, Comfortable, Soft, Very Soft or Inaudible by entering their response with the hand held Personal Selector, which is the identical recording device used with the original P3 system from ReSound.
The new LGOB application uses the patient's own digital hearing device or a stock "Digital Master" device to produce the sound stimulus directly from the Digital to Analog converter (DAC) within the hearing aid's Digital Signal Processor. No insert earphones are required. Either BTE or Custom In-The-Ear devices can be used to perform the LGOB loudness scaling measurements. The test protocol is initiated and controlled by connecting a Digital hearing device to a personal computer and using proprietary fitting software (ReSource II). When the fitting computer is disconnected, the hearing instrument functions normally.
Results from the test are used to provide fitting recommendations and initial device amplification parameter settings for the Digital 5000 and other programmable ReSound hearing devices.
(Please do not write below this line - Continue on another page if needed)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use (Per 21 CFR 801.109)
OR
Over-The-Counter Use
Page 1
(Division Sign-Off)ress
Division of Reproductive, Abdominal, ENT,
and Radiological Devices
K981547
510(k) Submission: ReSound digital LGOB
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.
