Making sense of Mexico City's traffic honks and horns

An Aztec skull whistle discovered in the 1990s was mistaken for a toy

In the late 1990s, archaeologists unearthed a sacrificed man clutching two skull-shaped clay whistles at a Mexico City temple to the wind god Ehecatl (eh-HEH-kahtl). Initially dismissed as toys, the instruments produce a scream-like sound that modern brain scans show triggers fear and urgency responses in listeners. This podcast explores the discovery.

The evolution of Mexico City, from the Aztecs to today

The sprawling modern city situated in the Valley of Mexico began a millennium ago as an island in the middle of Lake Texcoco, connected to land through a series of causeways. Learn how the Aztecs built Tenochtitlan, how the Spaniards conquered it, why the lake disappeared, and more with this visually rich history and geography of a city of 9 million people.

An interactive sound map of 8,000 locations around the world

Cities and Memory's global sound map covers 140 countries, featuring paired recordings: original field captures of a moment in time and an artist's recomposition built from the same source. The structure treats every location as both document and raw material, giving 2,500 contributors the same prompt with unpredictable results.

Noise pollution from humans and technology alters animal behavior

Animals may experience chronic stress and health issues due to noise pollution, which often interferes with their mating sounds. Due to traffic, nightingales sing louder on weekday mornings, and birds near airports start singing earlier to avoid upticks in takeoffs and landings.

Foghorn honks helped duckbills set the mood

Examining the unique crest of the Parasaurolophus, which researchers think allowed the creatures to emit loud, unique vocalizations as part of their social interactions.

How congestion pricing is trying to fix downtowns

Billions of gallons of gas are wasted each year as US drivers sit in traffic losing billions of hours of time. The congestion problems big downtowns face has led to innovative interventions to try to stop the traffic, including congestion pricing, a...

See this graphic describing what different decibel levels mean for hearing loss

From the sound of a ticking watch, which is roughly 20 decibels, to the sound of a gunshot at 140 decibels, the Hearing Health Foundation breaks down the decibels of daily sounds in this chart, noting that sounds louder than 70 decibels are considered harmful.

The features that make our voices unique

Human voices are about as unique as fingerprints: similar instruments but with endless variations. We each produce sound in the same physiological way, but when we talk we’re dropping clues about who we are, what we do, and where we’re from.

An overview of drugs, crime, and cartels in Mexico

In 2006, the Mexican government launched a war on the drug cartels. The cartels and the drug trade fuel rampant corruption and violence in Mexico, contributing to tens of thousands of homicides in the country each year. Mexican drug cartels are also...

In the 1930s, New York banned buskers as part of an antinoise campaign

Mayor Fiorello LaGuardia was hoping to modernize the city and believed that street performers only crowded the streets and added to an annoying cacophony. Residents wrote to the mayor to protest the decision, arguing that buskers were appreciated by the public.

The drama of the car dealership quota

Car salespersons are often under a ton of pressure to meet quotas at their dealership, at least partly explaining why they are known to stoop to such lows to sell cars. In this now legendary podcast episode, "This American Life" host Ira Glass and...

A comprehensive taxonomy of American tacos

Tacos may be a Mexican food, but they're wildly popular in America and in a number of different styles. This lengthy guide from Serious Eats was compiled after visiting more than 1,000 taco shops. It breaks down the differences between the many variations on the form (including breakfast, barbacoa, and Deli Mex) you'll encounter in different regions of the country. We don't recommend reading on an empty stomach!

Audi spent over three years developing engine sounds for its electric vehicles

Unlike the sounds made by combustion engines in gas-powered vehicles, electric cars produce no motor sounds. The company's acoustics team worked with composer Rudolf Helpmier to craft an electric-inspired revving sound for its R8 e-tron supercar.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Tinnitus is derived from the Latin verb tinnire, meaning to ring

Read the entry in The Physical Dictionary by Stephen Blankaart, from 1693, where the word first appeared in English.

Breaking down the music theory of Hitchcock's 'Psycho'

One of the defining features of Hitchcock’s film “Psycho” (1960) is the music, especially the sounds you hear during some particularly grisly scenes. This analysis from The Music Professor analyzes how that music complements the film, highlighting the way strings match the intensity of the film’s screenplay and black-and-white cinematography.

An anthropologist spent years riding garbage trucks to understand what our trash says about us

Robin Nagle rode with New York City sanitation workers to trace the hidden life of what we throw out. Her research explores what the things we discard reveal about who we are. 1440 explores the hidden life of trash.

Misfired motor signals may explain why many people with schizophrenia hear voices

Up to 80% of schizophrenia patients may have auditory hallucinations. Recent research concluded that this symptom may be from misfired motor signals that feed into each other, essentially failing to suppress certain sensory neural activities and that resulting overexcitment fuels hallucinations. The finding suggests that, one day, magnetic pulses might be used to stimulate specific nerves to better regulate the errant signals and reduce or stop hallucinations. (Some users may encounter a paywall.)

A 2,000-year history of alarm clocks

Clocks have revolutionized the way we live, structuring our days into abstract, regular units and providing quantification for those who are chronically late. The alarm clock was the next obvious step: clocks which not only tell you the time but...

Go behind the scenes of a 911 dispatch center

This video follows a dispatcher at a Colorado communications center serving over 1,600 square miles across four counties, showing the constant communication and relentless pace of a 24-hour shift on the other end of your emergency call.

How radio works

Antennae tune a radio to a particular frequency (determined by the listener on their radio's dial) while tuning out all the other stations being broadcast. AM, short for amplitude modulation, and FM, short for frequency modulation, decode audio signals differently, leading to differences in sound quality and the distance a station can travel.

An ethnomusicologist breaks down bossa nova's American popularity

Kaleb Goldschmitt is a professor at Wellesley College who wrote the book "Bossa Mundo: Brazilian Music in Transnational Media Industries," which analyzed how and why bossa nova became so popular in the US in the early 1960s. According to Goldschmitt, much of it was due to the music's seemingly apolitical aesthetic, a notion that was reinforced by the Brazilian government.

Container ships are just a fraction of total traffic via the canal

While more container ships traverse the canal than any other type of ship, vessels carrying dry bulk goods, vehicle carriers, chemical tankers, passenger ships, and more also pass through the Central American passageway.

The internet explained at five levels of difficulty, from protocols to internet flattening

Resembling a roadway with traffic laws that all cars must follow, the internet is the hardware that connects a source to a destination, and these connections must follow specific software rules. Although data had to travel through about 10 networks to reach a destination in the past, data centers increasingly consolidate traffic, just as a highway does for cars, to improve data speeds.

Hear the reasoning behind Trump's resurrection of the Monroe Doctrine in 2025

This podcast examines the Monroe Doctrine, from its casual origins in an 1823 congressional update to Trump's "Donroe Doctrine"—highlighting how fears of Chinese influence, concerns over oil prices, and the pursuit of hemispheric dominance influenced the administration's policies toward Latin America.

Burning Man's DMV refers to the Department of Mutant Vehicles

There's a specific Burning Man lingo that can be hard to follow if you haven't attended before. MOOP essentially refers to litter, the playa is another word for Black Rock City, and a playa chicken is a mythical deadly chicken.

Fireworks make a loud booming sound after exploding due to air expanding faster than the speed of sound.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Hear 50 years of iconic hip-hop samples, the genre's foundational looped tracks

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

American short story writer Flannery O'Connor raised 40 peacocks, which became potent symbols for her fiction's elegant violence

Quincy Jones' 'Big Band Bossa Nova' helped introduce bossa nova—a jazz-influenced Brazilian genre—to the US

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

A Yale student wrote a profound essay about the consulting industry's influence on elite college students that was published in a book of her writing after she died in a post-graduation car accident.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.