EPISODE 97
HBK Do Physical Domain Acoustic Metrics Translate Well to Human Perception?
Vince Rey of Hottinger Brüel & Kjær (HBK) joins again from California to discuss the Buzz, Squeak, and Rattle or ‘BSR’ test audio quality metric. It was developed by Dr. Wookeun Song (HBK). This BSR metric relies on deconvolution and time-varying loudness sound quality, considering frequency and time masking on the human ear. It can be summarised as ‘Does the measurement curve match the perception of the sound quality and how can we correlate the two?’
EPISODE 96
Elevear – Audio Algorithms Occlusion Effect Cancellation, Idle Noise Reduction, Edge Spatial
Stefan Liebich of Elevear joins to discuss their audio algorithms for hearables that cover occlusion, idle noise, and immersive 3D audio. Developed over many years and now being commercialized with key silicon partners.
OCCLEAR® TECHNOLOGY NATURAL OWN VOICE THROUGH OCCLUSION CANCELLATION
Existing headphones isolate the user from the environment, making their voice sound boomy and unnatural to them. This phenomenon is due to the occlusion effect, which attenuates air-conducted sound while amplifying body-conducted sound. A headphone user who is unhappy with the unnatural sound of their own voice. A headphone user who enjoys a natural own-voice sound thanks to the Occlear® technology. Our Occlear® technology eliminates the occlusion effect, allowing hearables users to perceive their voice and environment with natural clarity. Occlear® requires no specialized hardware and can be integrated seamlessly into ANC-ready hearables via a simple firmware update.
IDLE NOISE REDUCTION TECHNOLOGY WORLD-CLASS HISS-FREE TRANSPARENCY FOR YOUR HEARABLE
Hearables users often complain about microphone noise or hiss when using transparency mode. It stems from the low-cost, miniature microphones used in today’s hearables. To mitigate this noise, manufacturers often limit the bandwidth of their transparency mode, compromising the clarity of the sound. Our patented Idle Noise Reduction (INR) technology reduces the noise floor of hearable microphones by 10–15 dB, matching the performance of high-end studio microphones. The INR removes the hiss, allowing hearables manufacturers to achieve world-class transparency with low-cost components.
IMMERSIVE 3D AUDIO TECHNOLOGY INSTANT, UNALTERED 3D AUDIO WITHOUT LATENCY OR DISTORTION
Existing spatial audio solutions often struggle with head movement, resulting in a lag that disrupts the immersive experience. They also tend to compromise sound quality by adding reverb.
With imperceptible motion-to-sound latency, our algorithms ensure that the audio keeps pace with your every move. This seamless integration means you experience the world of sound most naturally as you navigate through it. Experience unaltered, high-fidelity audio that runs directly on your hearable device—no need for complex stack adjustments, including Bluetooth and app dependencies.
EPISODE 95
B&K 5128 HATS Simulator with their new 4620 Coupler Improve Upon the 711 Coupler Standard
HBK – Hottinger Brüel & Kjær’s Vince Rey joins to discuss their new 5128 head & torso simulator (HATS) plus their 4620 couplers.
HBK was formed in 2019 by merging two market-leading organizations: HBM and Brüel & Kjær. Both companies have over 80 years of experience providing innovative and high-quality solutions in precision test and measurement technology for various industries.
EPISODE 94
Echosonic – Bringing Edge Computing to MEMS Microphones for Efficiencies, Power Saving and Speed
Marie-Eve Desrochers joins to introduce their technology that targets to bring efficiencies and speed to the edge in MEMS microphones. Echosonic aims to develop next-generation MEMS smart microphones using reservoir computing technology to enable on-sensor audio signal processing using machine learning for both inference and software upgrading.
EPISODE 93
Audio Precision – APx516B Analyzer Quality Meets Affordability in Analog & Digital Audio Test
Dan Knighten, Product Line General Manager at Audio Precision joins to talk about their new low-cost APx516B Audio Analyzer.
With the proliferation of digital audio interfaces, there’s an increasing need for a straightforward, budget-friendly analyzer for both digital and analog audio testing. The APx516B Series Audio Analyzer offers a cost-effective modular solution for electronic audio customers, upholding the Audio Precision standard of performance and service. Designed for extended R&D teams and production test applications, the APx516B delivers comprehensive testing for analog and digital audio in a versatile, affordable package. Learn how the hashtag#APx516B can integrate into your testing solution.
EPISODE 92
Listen Inc – Correlating Transient Distortion Measurements with Audibility Enhanced Loose Particles eLP
Steve Temme of Listen Inc. joins us for part 2 of the discussion. In this segment, Steve explains their algorithms for end-of-line production testing for detecting if you’ve got some particles or even a screwdriver left in your speaker from manufacturing. Listen is a world leader in audio and electroacoustic testing and measurement. Founded in 1995, when its flagship product, SoundCheck® was launched, the company has pioneered electroacoustic measurement techniques for 20 years and sets the standard in the marketplace with powerful and innovative test methods and algorithms, fast and flexible testing, and excellent service and customer support.
EPISODE 91
Listen Inc – Perceptual Algorithms for End-of-Line Test – Enhanced Perceptual Rub & Buzz ePRB
Steve Temme of Listen Inc. joins us for part 1 of a two part discussion. In this segment, Steve explain’s their algorithms for end-of-line production testing for Rub & Buzz in speaker manufacturing. Listen is a world leader in audio and electroacoustic test and measurement. Founded in 1995, when its flagship product, SoundCheck® was launched, the company has pioneered electroacoustic measurement techniques for 20 years and sets the standard in the marketplace with powerful and innovative test methods and algorithms, fast and flexible testing, and excellent service and customer support.
EPISODE 90
Echo Test + Measurement Apple II to Firewire to USB Audio + AIO to Solving Production Testing
Matt Gonzalez and Kris Jackson from Echo Test + Measurement take us through the history of Echo and the ongoing evolution of building production line audio test equipment that keeps up with the pace of manufacturing.
EPISODE 89
Dinaburg Technologies C2S Speakers Active Driver with a Passive Ring Radiator Explained
Dinaburg Technology joins the THD Podcast this week to discuss their C2S speaker technology that combines an active driver with a passive ring radiator. This solution has a lot of benefits with in-wall and automotive applications and we have a panel of experts including Roger Shively of Shively Acoustics International and Mike Klasco of Menlo Scientific Ltd. to detail the explanation in this week’s episode.
Dinaburg Technology, based in Dallas, TX, was issued its first U.S. patent for an enhanced electro-dynamic loudspeaker design. Mikhail Dinaburg, a noted physicist and the patent inventor, uncovered some missing elements in Rice-Kellogg’s work and set out to prove it.
Dinaburg’s patent discloses techniques for higher-performance sound reproduction based upon Boyle’s Law. The design techniques enable lower distortion, extended frequency range, higher efficiency, and improved speech intelligibility. The invention has wide applications and scales from a 6 mm earphone driver to near-field studio monitors, to concert subwoofers.
EPISODE 88
Hypex Class D Amplifiers Designed with Discrete Components for HiFi Pro Studio
Niels Burema of Hypex Electronics in the Netherlands joins to explain the who, what, where, when, and why of their Class D power amplifiers, power supplies, DSP solutions, and plate amplifiers that they target into the HiFi, High End, and Pro Audio industries. A very good episode that is worth a watch to learn about the high end amplifier market.
EPISODE 87
Trulli Audio Thin Drivers Based on Perimeter Driven Technology Innovative Speaker Design
Trulli Audio joins the THD Podcast this Monday to explain their Perimeter-Driver Technology. It’s called Thin Driver™ and it is a concept a lot of us have imagined but these guys are making it happen. They’ve flipped the lid on motor design and I encourage you to watch/listen. A great conversation with Jordan Neuhauser and Andrew Briggs to learn about how the technology works and how it can make your products better.
Thanks to Barry Vogel and the ALTI Audio & Loudspeaker Technologies International for their support as well!
EPISODE 86
The Lyceum A Living Data Management System for Audio Product Development
We learn about The Lyceum which is a collaboration tool to manage acoustic data. Data is unique and it quickly gets lost in the shuffle moving towards the next experiment in your audio product development pathway. The advanced data ingestor of the Lyceum allows users to pick and choose what parts of their data get uploaded, and define how it can be searched for in the future! A management tool with audio data in mind that covers data sources from all standard development tools.
EPISODE 85
DBX-TV Superior Sound Enhancement From the Consumer Audio Experts
Tim Brault from dbx-tv joins to tell us about their history and expertise in audio signal process. DBX-TV’s solutions maximize audio quality from a television or other existing speakers, using the audio DSP already inside, so you can deliver a superior audio experience at a minimal cost. An exciting technology with universal benefits across all audio product development projects.
dbx, BTSC, and THAT Corporation
dbx-tv’s roots trace back to the early1980s at dbx, Inc., then a wellspring for a wide range of innovative, award-winning audio designs and products. Some of dbx, Inc.’s creations, including dbx compressors (as exemplified by the famous dbx 160 and its variants), are prized and sought-after to this day. dbx compressor/limiters are used throughout recording studios and in live performances.
One of dbx, Inc.’s many noteworthy inventions was its Emmy®-award-winning dbx-tv noise-reduction system designed to be an integral part of the BTSC (Broadcast Television Standard Committee) transmission system. BTSC became the standard for analog TV-audio broadcasts in North America in 1984, with many other countries adopting BTSC variations shortly thereafter. This single invention allowed hundreds of millions of consumers to experience TV in stereo with high fidelity and no loss of coverage in fringe areas.
In 1989, dbx, Inc. was divided into several parts, three of which remain today. The first part of dbx, Inc. to spin off was THAT Corporation. Three engineers from dbx, Inc. formed THAT to design and sell circuit-board-level implementations of dbx Inc.’s technology as well as sophisticated analog ICs to perform audio functions. THAT’s first products included circuit boards to implement the dbx-tv noise reduction system for professional broadcast equipment makers, and voltage-controlled amplifier (VCA) and rms-level detector ICs for pro audio equipment makers. Twenty years later, those same three engineers remain the principal owners and managers of THAT today.
Shortly after THAT spun off, the professional products division of dbx, Inc. was sold to AKG, which was subsequently purchased by Harman International. Along with brands like AKG, JBL, Soundcraft, and Studer, dbx Professional Audio Products is a prominent part of Harman’s professional audio business.
Finally, in 1994, the dbx-tv licensing program was purchased by THAT Corporation, reuniting some of the original engineers involved in its development with the business that came from this technology. Since then, THAT has greatly expanded the scope of dbx-tv, enhancing its value with new digital variations of legacy reception. Most recently, THAT has introduced a new technology suite (dbx-tv Total Sonics and Total Volume) to address common audio problems with all modern broadcast reception.
EPISODE 84
BT Headphone Production Testing: Insights from APDA Webinar
We have a replay of a recent Audio Product Development Alliance Webinar on BlueTooth Headphone Production Testing. Today, we are honored to have Simon Weston from Zumi Systems presenting on the intricacies of BT headphone production testing. As we all know, Bluetooth headphones have become increasingly popular in recent years, and with this surge in demand comes a greater need for reliable and efficient testing methods. Simon Weston, with his extensive knowledge and experience in audio product development, is here to guide us through the quirks of BT headphone production testing and share with us some of the best practices and industry insights. So without further ado, let’s welcome Simon Weston and learn more about the challenges and solutions for BT headphone production testing.
EPISODE 83
IDUN Brain-Sensing Earbuds that measuring neural activity EEG
Mark Melynkowycz, the lead product designer, from IDUN Technologies joins to talk about their EEG technology for earbuds and what it can bring to the market of hearables.
IDUN Technologies is a neurotech Start Up and their vision is to create a more connected and empathetic world using in-ear EEGs. The Guardian Neuro-Intelligence Platform is a Brain-computer Interface that provides real-time measurements of neuro markers, enabling partners to improve their products and services using innovative technology.
EPISODE 82
GRAS EQ 40PM Miniature Production Line Microphone 1st Mic Using EQset Technology
Rémi Guastavino the Director of Product Management at GRAS-Sound & Vibration joins to tell us about the use case and benefits of the new EQ 40PM. The GRAS EQ 40PM is a robust, cost-effective microphone designed for use in production line testing of loudspeakers and acoustic transducers. It has a wide frequency range, from 20 Hz to 20 kHz, and a dynamic range from 30 dB (A) to 120 dB. EQset incorporation in a microphone removes all of the traditional hassle associated with installing, setting up, and replacing microphones in a production line setting. EQset microphones all have flat response curves and fixed sensitivity. Sensitivity variation between individual microphones varies less than 0.2 dB from nominal sensitivity. The flat frequency response is less than 0.5 dB up to 10 kHz, another huge improvement over traditional production line microphones ±3 dB across the full frequency range. This provides a number of immediate benefits.
Cost efficiency—low microphone entry cost, no special hardware needed, and fully backward compatible with CCP setups.
Ease of use—a uniformly flat frequency response fixed sensitivity (or gain) for each EQset microphone makes EQ 40PM microphones plug and play in any 48 V phantom power or CCP-based setup.
Reduced risk—the extremely narrow pressure response spread (±0.5 dB) greatly reduces the risk of false passes and false failures, which greatly reduces the risk of bad units reaching the customer and the risk of good units being scrapped or recycled.
High environmental stability—the unique design of the EQ 40PM provides this range of microphones with unmatched environmental stability. Deviation on a typical production line is less than ±0.3 dB, so there is no need for corrections due to temperature or humidity.
EPISODE 81
SONIC EDGE A PURE DIGITAL MEMS SPEAKER
Sonic Emotion’s CTO and CEO join to explain their MEMs speaker technology. Conventional speakers require a balance between mechanical, acoustical, and electrical resonances. As a speaker shrinks in size, keeping the resonance balanced is a complex challenge and the quality of sound is compromised.
We have developed a unique technology that, instead of attempting to solve the problem, actually turns it on its head. Our unique technology generates ultrasound from multiple speakers, each as wide as a strand of hair, and then transforms the ultrasound to sound using a patented acoustic-mechanical frequency transformer.
The ultrasound speakers and frequency transformers are realized as solid-state MEMS devices. The MEMS device is manufactured using semiconductor technologies leveraging the semiconductor ecosystem for scalability and price trajectory. The outcome is clear: maximum sound quality in minimal size.
EPISODE 80
AUDIOSCENIC Virtual Headphones Using Headtracking and Advanced DSP
Dr. Marcos Simon, CTO and Co-Founder of AudioScenic joins the podcast to explain their groundbreaking technology. Audoscenic delivers immersive 3D audio through cutting-edge technology & innovation. They have adapted audio to people to create the perfect listening experience. Our proprietary loudspeaker array technology, head-tracking, and AI capabilities create a personalized, user-adaptive, and best-in-class immersive sound.
EPISODE 79
ZUMI Headphone Test & Measurement System Frequency Response Comparison SONY SENNHEISER B&W BOSE
Simon Weston switches to the presenter to detail how the ZUMI HPA86 Test and Measurement System works. We compare frequency response measurements from SONY, SENNHEISER, BOWERS & WILKINS, and BOSE headphones. The procedure of demonstrating the test shows the ease of use of the ZUMI HPA86.
EPISODE 78
Andrew Bellavia of AuraFuturity Gives a Technical Introduction to the Hearing Health Market Category
Andrew Bellavia a veteran with technologies that go in your ear joins us to explain what is hearing health. We touch on some of the history of the technologies in the legacy devices and we explore the direction the markets are going with the convergence of audiology-grade products with consumer-grade products.
EPISODE 77
Sonical – CosmOS Operating System That Enables Computer Functionality on Earbuds, Headphones
Gary Spittle, CEO from Sonical, joins to explain the concept plus the possibilities that adding an OS to earbuds/headphone endpoints can bring. The ability to load applications to customize headphones is an exciting approach that is coming to products soon.
EPISODE 76
Mosomic – The MEMS Microphone book
Mikko Suvanto joins to discuss his history in audio, microphones, specifically MEMS microphones and he tell us about the book that he just published on everything you need to know about MEMS microphones.
In 2019-20, Mikko produced the ‘Mosomic MEMS Microphone Guide’, a 9.5-hour, 28-episode free video tutorial on what MEMS microphones are and how to design outstanding and reliable sound capturing solutions with them. Find out more here:
http://www.mosomic.com/mems-microphone-guide/
In January 2022, Mikko published ‘The MEMS Microphone Book – A practical guide to reliable high-quality sound capturing with miniature microphones’. It’s based on the MEMS Microphone Guide video series but has a lot more depth and a wider scope. More information and links to buy the book can be found here:
http://www.mosomic.com/thememsmicrophonebook/