If a tree falls in a forest does it make a sound?
If a tree falls, and there’s no-one there to hear it, does it make a sound? An age old question that’s puzzled for centuries. Can CrowdScience settle it once and for all?
If a tree falls in a forest, and no-one is there to hear it, does it make a sound? This is an age-old debate that listener Richard and his family have been arguing about for years. Can CrowdScience settle it once and for all?
Caroline Steel speaks to experts in hearing, biology, philosophy, physics and sound design, which takes her to some unexpected places.
Professor Stefan Bleek is an expert in psychoacoustics who says that sounds only exist in our heads.
Dr Eleanor Knox and Dr Bryan Roberts are philosophers that make her question if anything exists outside our own perception. Professor Lilach Hadany wonders if it’s limited to humans and animals - could other plants hear the falling tree too?
And Mat Eric Hart is a sound designer who says that sound is subjective – it’s always tangled up with our own interpretations.
Things get truly weird as we delve into the strange implications of quantum physics. If there is such a thing as reality, doesn’t it change when we’re there to observe it? Does the tree even fall if we aren’t there?
Presenter: Caroline Steel
Producer: Anand Jagatia
(Image: Fallen Tree. Credit: Getty Images)
Last on
More episodes
Previous
Clip
![]()
Is sound just in my head?
Duration: 02:21
Broadcasts
- Fri 2 Apr 202119:32GMTBBC World Service
- Sat 3 Apr 202101:32GMTBBC World Service East Asia
- Mon 5 Apr 202104:32GMTBBC World Service Americas and the Caribbean, Australasia, South Asia & East Asia only
- Mon 5 Apr 202108:32GMTBBC World Service
- Mon 5 Apr 202112:32GMTBBC World Service except East and Southern Africa, East Asia, South Asia & West and Central Africa
- Fri 29 Jul 202219:32GMTBBC World Service except East and Southern Africa & West and Central Africa
- Sat 30 Jul 202201:32GMTBBC World Service Europe and the Middle East
- Sun 31 Jul 202201:32GMTBBC World Service East and Southern Africa & West and Central Africa only
- Mon 1 Aug 202203:32GMTBBC World Service Australasia, South Asia & East Asia only
- Mon 1 Aug 202204:32GMTBBC World Service Americas and the Caribbean
- Mon 1 Aug 202208:32GMTBBC World Service
- Mon 1 Aug 202212:32GMTBBC World Service except East and Southern Africa, East Asia, South Asia & West and Central Africa
- Mon 1 Aug 202219:32GMTBBC World Service East and Southern Africa & West and Central Africa only
Podcast
![]()
CrowdScience
Answering your questions about life, Earth and the universe


