Season 2 Episode #21: What happens when a hi-fi hobbyist who was manufacturing driver's licenses gets a tip from his brother about a new audio lab being built at Skype? Ergo Esken, Principal Software Engineering Manager at Microsoft, shares how that moment launched nearly two decades of ensuring the call quality millions of people take for granted every day.

We explore why getting hardware right still matters more than most people realise, how design teams wanting thinner devices force engineers into impossible tradeoffs, and what it actually looks like to test a call using head and torso simulators in anechoic chambers. We also dig into why users blame the platform, not the device, how you write test specs for ML features that behave differently every time, and why algorithms will happily calculate numbers from completely scrambled audio that only a human can catch.

From taking apart hi-fi equipment to testing calls for millions - how a hobby and a brother's tip became a two-decade career

His audio obsession started in secondary school, but his career detoured through manufacturing bank cards and driver's licenses before his brother pointed him to Skype
Skype solved the VoIP firewall problem and slashed international calling costs from hundreds of euros to free
What was niche in 2007 is now the default - video calling is just expected
Nearly 20 years in one role sounds long, but the technology changes fast enough to keep it interesting

The invisible hardware war - why thin devices, hidden loudspeakers, and distant microphones still define call quality

A loudspeaker under a keyboard rattled keys at specific female speech frequencies - the kind of problem only found in design verification testing
Cameras squeezed into 2mm laptop screens and microphones moved a metre from your mouth force constant tradeoffs between design and quality
When a call sounds bad, users blame Teams or Skype, not the device - which is why platform-side hardware certification exists
Machine learning compensates for shrinking hardware, but raw hardware quality still sets the ceiling

Testing the real world in a lab - dummy heads, silent rooms, and making results match across the globe

Head and torso simulators with artificial ears and mouths simulate real calls, and those rubber ears expire after three to four years
Anechoic chambers sit on springs, use heavy walls, and line every surface with foam to eliminate outside noise and reflections
Round robin tests send the same device to labs worldwide without sharing results to verify consistency
Simulating a 30-person conference room with simulators is too expensive, so the team targets known weak points instead

ML features that behave differently every time - and why a human still has to watch and listen

Noise cancellation can now hide a vacuum cleaner, but reverberant rooms remain a challenge for algorithms
Devices that learn one specific voice create entirely new testing problems for simulators built around generic test signals
Algorithms calculate numbers from scrambled audio regardless - only a human can hear that something is wrong
AI coding tools changed the game for a non-programmer, but the experience to spot bogus numbers is still irreplaceable

Ergo Esken

Principal Software Engineering Manager at Microsoft

Ergo Esken has nearly two decades of experience in audio video quality engineering, joining Skype's audio lab in 2007 and continuing through the Microsoft acquisition to his current role. His work centres on building end-to-end test setups with specialised equipment to ensure the calling experience millions of users expect from Microsoft Teams. Outside of work, he builds hi-fi loudspeakers, 3D prints components, and documents his projects on enthusiast forums - hands-on skills that give him an edge when wiring together complex test setups that most software engineers would rather not touch.

Josh William Burmistre-Griffiths

Digital Marketing and Paid Ad Specialist

Josh William Burmistre-Griffiths works at TestDevLab, focusing on digital marketing and paid advertising across multiple platforms. His past experience working at agencies and unicorn startups in Latvia has equipped Josh with the expertise and a unique perspective that combines hands-on experience with a deep understanding of how technology shapes modern marketing practices. Helping him bring valuable digital marketing insight to the Tech Effect podcast.

#40 Ergo Esken (Microsoft): The Hardware and Science Behind Sounding Good on a Call

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