The major focus in my professional life has been the development of perception based Quality of Experience (QoE) measurement and optimization techniques (see left/top picture).
I started my career in 1974 with an internship on the topic of intonation at the IPO (PHILIPS Eindhoven, see photo).

I have degrees in electronic engineering (ing), physics (MSc) and psychophysics (PhD). My biggest achievements are:

After finalizing my masters in physics at Leiden University I have (co)-developed measurement algorithms/procedures for the assessment of:
    Pitch Probability Density (NWO/IPO/PHILIPS) PhD, Chapter 5
    Speech Quality (KPN/OPTICOM/TNO) EXAMPLES ITU-T Rec. P.861 PSQM;   P.862 PESQ;   P.863 POLQA open access         POLQA flowchart  
    Speech Quality Degradation Decomposition (TNO) Degradation decomposition into noise, time, frequency domain contributions
    Speech Quality of Tone Languages (TNO, uni Nsukka) The Impact of Tone Language and Non-Native Language Listening on Measuring Speech Quality
    Speech/Telephony/Audio/Video Quality (KPN/TNO) Glass Box versus Black Box Telephony example, see also GSM example
    Talking Quality (listen to your own voice) (KPN, uni Delft) PESQM
    Conversational Quality (TNO uni Nsukka) ITU-T White Contribution; Conf paper Acoust. Soc. of Nigeria
    Intelligibility (TNO/KPN) PESQ Intelligibility;    POLQA Intelligibility
    Audio Quality (KPN/OPTICOM) PAQM (output example);    ITU-R standard BS.1387 PEAQ
    Video Quality (KPN/OPTICOM) PVQM;    ITU-T standard J.247 PEVQ
    AudioVisual Quality (KPN) (AA-Q,VV-Q) ➜ AVAV-Q
    Hearing Aid Quality (TNO/Consortium) PHAQM basic approach, Limited information available, see Figs 2 and 3 of this AES paper
    Loudspeaker Reproduction Quality (TNO/Consortium) PREQUEL
    Immersion Quality (TNO/Consortium)) EXAMPLES Under development  
    Browsing/Downloading Quality (KPN/TNO) Glass Box Browsing/Downloading, based on ITU-T standard G.1030

See also my Publications/Patents Curriculum Vitae Google Scholar pageLinkedIn Page,  and an interview in TNO magazine (2006 in Dutch  or English).

My non-professional life is focused on Quality (read my philosophy on measuring Quality) and for a part thus on audio quality,
see e.g. my view on HiFi published in 2007 in HiFi Video Test and updated/extended in English over the period 2012-2023:
1: Transparantie en Perceptieve Meettechnieken Transparency and Perceptual Measurement Techniques
2: De Weergave Filosofie “Hier en Nu” versus “Daar en Toen” Reproduction Philosophy “Here and Now” versus “There and Then”
3: De Ideale Luidspreker, Diffuus Veld Egalisatie The Ideal Loudspeaker, Diffuse Field Equalization
4: De Ideale Luidspreker, Reflecties en Resonanties The Ideal Loudspeaker, Reflections and Resonances
5: Audio Compressie Audio Compression
6: Subjectief Testen Subjective Testing
7: Wat Willen We What Do We Really Want?, Immersion!
8: Telefonie Telephony
An overview of conversational quality and music reproduction quality is given in this HiFi over WiFi paper (only available in Dutch)

Or, when shifting towards content quality, listen to my 1 hecto second (1 hs) music taste linkers chosen on the basis of their combined
spectacularity and stability quality score, read my philosophy on measuring Quality       (quality limited by MP3 compression) :
1722 J. S. Bach (Sviatoslav Richter 1972) / Well Tempered Clavier / Prelude & Fugue No. 08 BWV 853
1731 Vivaldi (Jakob Lindberg 1985) / Concerto in Re maggiore / Allegro giusto / RV93       (perfect acoustic capture by BIS)
1814 Beethoven (Hélène Couvert 2004) / Piano Sonatas / Sonate op.27 no 1
1896 Bruckner (Bernard Haitink 1965)/ Symphony no 9 / Scherzo
1940 John Cage (Donald Knaack 1989) / Three Constructions / Second Construction
1969 Frank Zappa / Hot Rats / Little Umbrellas
1973 Gentle Giant / In a Glass House / Experience
1977 Spirit / Future Games / Buried in My Brain
1980 Captain Beefheart / Doc at the Radar Station / Hot Head
1991 Pere Ubu / Worlds in Collision / Worlds in Collision
1997 Slapp Happy / Ça Va / Powerful Stuff
Naming convention = Composer (Interpreter) / CD / Song.

More 1 hs taste linkers can be found here
Or listen to some of my favorite hit single (guilty?) pleasures
Or to some hit and non hit modern classics
Or to some video clips where the video is dominating the perception

Or, when shifting away from quality, listen to some of my old private recordings in the 80's with low quality audio equipment:
Unknown marimba piece by Paul Jongsthover (recorded 1985, technical set up by Hans van Beekhuyzen )

Rain pipe marimba algorithmic music by Leon van Noorden (recorded 1985 using my Jecklin Disc like walkman recording bag)    link to Leon

Piano improvisation by Bart Dijkman (recorded 1982 using my home built tube condenser microphones)    link to Bart

My Turkish neighbors in the early 80's when MultiCulti still had a positive connotation (recorded in 1982 using my home built tube condenser microphones)

Karaoke Hauser Orkater door Ineke Beerends Hazebroek, Ton Willekes en Rasida Jahangir (recorded 1980 using my home built tube condenser microphones)    link to Ton Willekes Ensemble Pittorresque

My quick try-out algorithmic music construction (recorded 1987 using a Mac and Yamaha FB01 synthesizer)

Some of my favorite music video clips:
1966 Kinks - Dead End Street
1987 New Order - True Faith
1987 Interpol - The Heinrich Maneuver
1995 Radiohead - Street Spirit
2000 The Dandy Warholes - Godless
2006 Yeah Yeah Yeahs - Gold Lion
2006 Raconteurs - Steady, As She Goes
2006 Stromae - L’enfer 2022

Nederlandstalige muziek, ook gekozen op basis van de gecombineerde spectaculari-stabiliteit:
1965 Het / Ik heb geen zin om op te staan
1974 Drs P / Dodenrit
1976 Bots / Zeven dagen lang
1979 Hauser Orkater / Zie de mannen vallen
2001 Maarten van Roozendaal / Red mij niet
Maarten van Roozendaal /   Het Leven Heeft Geen Zin
2015 Broederliefde / Alaka

You may also want to watch some of my favorite live performances:
1968 Small Faces - Full Concert / UK, BBC
1968 Soft Machine - Full Concert / France
1968 The Mothers Of Invention (Frank Zappa) - Concert / UK London
1969 Fleetwood Mac - Man of the world / Germany, Beat-Club
1969 The Jimi Hendrix Experience / Sweden Stockholm
1970 Joni Mitchell - Woodstock / UK, BBC
1972 Captain Beefheart Concert / Germany, Beat-Club
1972 Pacific Gas and Electric - Are You Ready / Germany, Beat-Club
1985 Mink DeVille - Demasiado Corazon / Netherlands, Top-Pop
2010 Iva Bittova - Sirka v louzi / Netherlands, VPRO Vrije Geluiden
2013 Wire - Full Concert / USA Seattle, KEXP
2014 Thurston Moore - Full Concert / USA Seattle, KEXP
2016? Rogerio Tutti - Malagueña (Lecuona) / Brasil
2021 Mdou Moctar - Afrique Victime / Niger
2023 Buddy Guy | / Netherlands Rotterdam, North Sea Jazz

Moving further away from music towards art:
1612 Artemisia Gentileschi (The result of Me Too) / Judith and Holofernes
1658 Johannes Vermeer (Paint the Light) / Milkmaid
1887 Antonio Mancini (Paint the Women) / Aurelia
1914 Jan Mankes (Paint The Truth) / Young white goat
1921 Paul Klee (Paint the Essence) / Adam and Little Eve
1944Piet Mondriaan (Abstract Ultimo) / Victory Boogie Woogie
1987 Madi Phala (Black Artists matter) / These Guys Are Heavy
1999 Francis Alÿs / El Ensayo (Multi Media, Should be experienced in surround)
2000 Ingrid Sikkens (Personal Favorite) / No Title
2015 Tereza Rullerova / Playbour Supersonik (Multi Media)

Best talks in the search of the basics we need to understand the world:
2007 Why the universe seems so strange | Richard Dawkins | TED, Monterey USA
2010 Visualizing Eleven Dimensions | Thad Roberts | TEDx Boulder USA
2013 The Particle at the End of the Universe | Sean Carroll | The Royal Institution, London UK
2013 The most important lesson from 83,000 brain scans | Daniel Amen | TEDx Orange Coast
2014 How to Love Intelligently In the Age of Instant Gratification | Sue Johnson
2014 Mathematics as Hidden Reality | Edward Frenkel | Science and Non Duality
2015 How dogs love us | Gregory Berns | TEDx Atlanta
2015 Have we reached the end of physics? | Harry Cliff | TED Global, Geneva CH
2016 The most mysterious star in the universe | Tabetha Boyajian | TED, Vancouver CA
2016 Why Does Time Exist at All? | Sean Carroll | TEDx Caltec
2016 What is the best diet for humans? | Eran Segal | TEDx Ruppin
2017 De maatschappelijke oorzaken van burnout | Paul Verhaeghe | Socius, steunpunt sociaal-cultureel werk vzw, NL
2017 Nihilism - There’s an App for That! | Nolen Gertz | TEDx, Frankfurt D
2017 Quantum Fields: The Real Building Blocks of the Universe | David Tong | The Royal Institution, London UK
2018 Quantum Computing: Untangling the Hype | Artur Ekert and Harry Buhrman| The Royal Institution, London UK
2018 Lessons from a Tiananmen Massacre Survivor | Jianli Yang | TEDx Carnegie Mellon, Pittsburgh USA
2019 Super ethics or super intelligence | Pim Haselager | Donders Institute, Nijmegen NL
2024 Consciousness in humans and other things | Anil K Seth | The Royal Society, UK