# 732. バイリンガルニュース 10.08.26

- Show: バイリンガルニュース (Bilingual News)
- Published: 2026-10-08
- Canonical: https://podc.club/en/episode/653415937_582edd253387.html
- Audio: https://traffic.libsyn.com/secure/bilingualnews/100726.mp3?dest-id=154797
- Source: Edited from a machine transcript of the first 30 minutes of the episode. Not an official summary.

This episode covers two topics: a University of Massachusetts Amherst study confirming that Brazil's White Bellbird and red-footed screaming piha produce calls exceeding 120 dB—rivaling ambulance sirens and jet engines—and an Ohio State University survey of 1,858 adults on how comparing one's current appearance to past photos affects body image. The conversation also expands into how smartphones in the digital age force unintentional self-comparison by automatically surfacing old memories.

## What this episode answers

### Which species hold the title of world's loudest bird, and how loud are their calls?

Brazil's White Bellbird and red-footed screaming piha both exceed 120 dB, with the White Bellbird peaking at 130 dB—approaching the roughly 140 dB of a gunshot and rivaling ambulance sirens and airplane engines, loud enough to cause hearing damage up close.

### Did researchers determine why these birds evolved such extraordinarily loud calls?

Researchers tested three hypotheses—compensating for obstructed forest sightlines, channeling energy saved by poor flight into calls, and attracting more mates—but none showed a significant correlation across the 123 species studied, leaving the reason unknown.

### How does comparing one's past appearance to one's current self affect body image?

People who more strongly feel their past self was more attractive show stronger negative body image and shame about their current body; those who feel better about themselves now report higher self-esteem and positive self-assessment—the problem is not comparison itself but reaching the conclusion that 'the past was better.'

### How does the digital age—with smartphones automatically surfacing old photos—influence self-comparison?

Smartphones automatically send notifications like '5 years ago today,' greatly increasing unintentional encounters with past images; unlike the analog era, when seeing old photos required deliberately pulling out a heavy album, those photos are now always within reach.

### What discussion arose around technology that continuously records everything, such as brain chips?

A paradox was discussed: if everyone continuously records their visual field via brain chips, there would be no need to take out a smartphone to capture a moment; the conclusion was that there are losses both in recording and in not recording, and that the value lies in still having the freedom to choose.

## Article

## The World's Loudest Birds — The White Bellbird and Red-Footed Screaming Piha

A research team at the University of Massachusetts Amherst measured the calls of 123 bird species across the United States and Brazil, confirming that Brazil's White Bellbird and red-footed screaming piha both produce calls exceeding 120 dB. The findings were published in the journal *Evolution*. For context, 120 dB is comparable to an ambulance siren or a jet engine.

Despite being roughly the size of a pigeon, the White Bellbird clocked a peak of 130 dB—approaching the approximately 140 dB of a gunshot. In a video the team posted to YouTube, a sharp metallic sound is audible, which one host described as sounding like "construction work—a clanging, clanking kind of noise." The red-footed screaming piha, by contrast, is a large bird standing 70–90 cm tall and weighing roughly 2 kg, about the size of a turkey. The study also found a general trend: the larger the bird and the wider it can open its beak, the louder its call.

## Why So Loud? — All Hypotheses Fall Short

The research team tested three hypotheses: (1) birds compensate for poor sightlines in forested environments by relying on sound; (2) species that are poor fliers can divert energy they save into their calls; and (3) louder calls help attract more mates. None held up. The red-footed screaming piha breeds in pairs, lives in open habitats where it is easy to spot visually, and yet calls extremely loudly. No correlation was found between predator density and call volume, and no significant relationship emerged from the full dataset of 123 species.

One host reflected on this by drawing a parallel to human variation: just as some people are naturally loud-voiced and some are quiet yet both survive, there may simply be no singular evolutionary reason—both strategies work. The conversation expanded to the stereotype of Americans being loud, how ambulance siren volumes vary considerably by country (with London's reportedly being far louder than Japan's—loud enough to make children cover their ears), and why train announcements use higher frequencies to cut through ambient noise.

## Comparing Past and Present Appearance — Ohio State's Survey

An Ohio State University study of 1,858 adults living in the United States moved beyond conventional social comparison—measuring yourself against others—to focus on what it called retrospective self-comparison: looking at old photos and feeling you looked better back then. Using an 11-item scale, the study found that people who more strongly felt their past self was more attractive showed a stronger association with negative body image and shame about their current body. Conversely, those who felt they looked better now reported higher self-esteem and more positive self-assessment. The problem is not comparison itself but the specific conclusion that "the past was better." This tendency is most likely to emerge during periods of significant physical change—aging, pregnancy, menopause, illness, or weight change.

One host noted that tracking your own progress over time is often more rational than comparing yourself to others—much like measuring language improvement against your own past ability rather than against someone else's. For physical appearance, though, she acknowledged noticing changes between her twenties and post-childbirth thirties, and that old photos now prompt thoughts like "I looked cute—my arms were so much slimmer." She was clear, however, that this registers as a neutral observation rather than a source of stress, and that she feels no desire to go back. The hosts also raised a separate perspective: comparing yourself to peers your own age offers a more contextually grounded benchmark.

## The Digital Age — The Double-Edged Record and the Right to Forget

In an era when smartphones automatically push "5 years ago today" notifications, people are pulled into unintentional self-comparison more often than ever. In the analog age, seeing an old photo required the deliberate effort of pulling out a heavy album. As one host put it: "If you'd never seen it again, you'd have forgotten—but because it's shown to you, you remember."

The hosts also connected this to a trend of young people no longer dancing at clubs, partly out of fear that footage will be captured and spread online. One host observed: "We must have been pretty cringe too, but it was never recorded, so it just disappeared."

The discussion then turned to a paradox: in a future where everyone continuously records their field of vision via brain chips, the smartphone itself becomes unnecessary—there would be no need to take it out. The episode concluded that there are losses both in recording and in not recording, and that what matters most right now is that we still have the freedom to choose.

## Takeaways

- Brazil's White Bellbird is the world's loudest bird at up to 130 dB, but why it—and the red-footed screaming piha—evolved such extreme calls remains unexplained even after studying 123 species.
- Ohio State's survey of 1,858 adults found that feeling your past self looked better than you do now is tied to negative body image and shame, while feeling you've improved is linked to higher self-esteem—the issue is the conclusion, not the act of comparing.
- The digitization of memory has eroded the freedom to forget by making old photos perpetually available, and the ability to choose what to record still carries real meaning while that choice remains.