Researchers discover mysterious whale recording from 1949 – what it reveals

In a dusty archive, a team comes across an unremarkable plastic disc - and a voice from the depths of 1949 suddenly speaks.

For decades, a plain cardboard box sat largely unnoticed in the basement of an American research institute. Inside was a delicate plastic disc, annotated like an overlooked office memo. When researchers finally placed it on an old playback machine, a low, eerie singing burst into life: believed to be the earliest recording of a humpback whale - captured in 1949 off Bermuda.

An archive discovery nobody was looking for

The recording comes from the archives of the Woods Hole Oceanographic Institution (WHOI) in the US state of Massachusetts. The collection holds thousands of reel tapes, handwritten notes and historic measurement records. During a systematic review, the chief archivist found a fragile plastic disc that had originally been intended for everyday office dictation - a so-called Audograph.

What’s on it begins as a rough, low-frequency rumble, followed by clear, drawn-out notes that line up like verses. To modern ears it unmistakably resembles whale song - yet at the time the disc was made, nobody really understood what had been captured.

"At the time of the recording in March 1949, the term ‘whale song’ was practically unknown in research."

Back then, the scientists were simply trialling sonar technology aboard a research vessel off Bermuda. The whale’s song ended up on the disc more by chance than design, filed away as an unexplained deep-sea interference.

Why this 1949 humpback whale voice is so exceptional

Specialists now believe this is the oldest known recording of a singing humpback whale. The clip is around 77 years older than many systematically collected whale-song datasets from the 1960s and 1970s.

Its value goes far beyond novelty. This single recording opens up several rare research opportunities at once:

• Insight into humpback whale behaviour during the early phase of modern ocean science
• Comparison of historic ocean sound levels with today’s noise-burdened marine environment
• Analysis of how whale songs change or adapt over decades
• A way to test whether other early “unidentifiable noises” in old archives were also whale song

The background sound is especially intriguing: the disc captures not only the whale, but the wider underwater ambience of the 1940s. Commercial shipping was far lighter then, huge container ships did not yet exist, and the offshore industry was still in its infancy.

What the seas sounded like then - and what they sound like now

Marine acousticians stress how difficult it is to reconstruct the ocean soundscape of past decades. Computer models can offer approximations, but genuine historic recordings are exceptionally scarce - many tapes from that era deteriorated, or were recorded over.

"The plastic disc survived the decades - a stroke of luck that is worth its weight in gold for today’s research."

Since the 1950s, noise levels in many ocean regions have risen dramatically. Key drivers include:

• dense shipping traffic involving large cargo vessels and cruise ships
• extraction of resources from the seabed
• military sonar systems and explosive detonations
• construction activity such as harbour works or wind-farm building

All of this noise can travel long distances through water. For marine mammals that rely heavily on hearing, the consequences can be severe.

Why noise can become life-threatening for whales

Humpback whales communicate across vast distances using complex songs. These sounds are used not only to find mates, but also for orientation and potentially for co-ordination within groups.

When background noise increases, the extreme outcomes can include:

Acoustic pressure	Possible consequence for whales
Continuous ship noise	Songs are masked; communication partially breaks down
Sudden bang-like sounds (e.g. detonations)	Panic responses, flight behaviour, disorientation
Powerful sonar	Damage to hearing; in extreme cases, strandings

The 1949 recording effectively provides an acoustic “before” snapshot. Compared with modern data, it makes it possible to examine how strongly humpback whales may have adjusted pitch, volume or rhythm to cut through the constant rumble of shipping.

How researchers are analysing the 1949 humpback whale recording

The first task was to digitise the brittle plastic disc. Specialists carefully cleaned the surface and played it using adapted equipment so the groove would not be further damaged. They then corrected speed and pitch, because older machines often ran far less precisely than modern recorders.

On computers, marine biologists are now breaking the song into individual sequences and examining, for example:

• Frequencies: what pitches does the whale use?
• Structure: do specific “verses” or patterns repeat?
• Duration: how long does the whale sustain a song?
• Comparison: where does it resemble modern humpback whale songs, and where does it differ?

Humpback whales are well known for changing their songs over time. In some regions, a new motif can spread like a hit track, rippling across entire populations. This historic recording may show how far back that process can be traced.

What the find reveals about research itself

The story of this chance discovery also highlights something less obvious: the importance of strong archival practice. Many datasets seem mundane or meaningless in their own time. Decades later, they can suddenly become pivotal.

"The disc lay unnoticed for years because nobody suspected it held a pioneering piece of marine biology."

The archivist argues that cases like this are exactly why measurement data should be preserved with care, even when there is no immediate research question. Today, those old sounds provide building blocks for questions that could not even be asked back then: how much have we already altered the oceans’ acoustic environment - and how much capacity do animals have left to adapt?

Why whale songs have captivated people for decades

By the 1970s at the latest, whale songs had developed a curious pull. Records featuring humpback whale vocalisations became bestsellers, and many people listened to them to unwind. They were treated as symbols of threatened nature - and they played a part in campaigns against commercial whaling.

That an even earlier recording has now surfaced touches precisely this blend of emotion and science. Listening to the 1949 clip can feel like eavesdropping directly on a long-vanished ocean world.

At the same time, it is a reminder of how little time separates that quieter ocean era from today’s industrial sea. In just a few decades, humans have thoroughly reshaped the sound of the oceans.

What we can learn from the “time capsule” for marine conservation

From a marine-conservation perspective, the historic recording could have tangible consequences. If researchers can demonstrate how strongly noise alters the structure of whale songs, it strengthens the case for quieter ships, tighter noise limits and protected zones where acoustic disturbance is restricted.

Some shipping companies are already trialling slower operating speeds or improved hull designs and propellers to reduce noise output. Such measures could become more common if it becomes clearer just how sensitively marine mammals respond.

Seeing the recording as a “time capsule” also carries a second message: even seemingly outdated technology - like an office dictation device - can become valuable decades later if it happened to capture the right data. That is true not only for whale research, but across many fields, from old weather logs to early satellite imagery.

To a lay listener, a droning, creaking sound from 1949 might seem unremarkable. In Massachusetts laboratories, it is now regarded as an acoustic window onto a quieter past - and a warning of how loud the seas have become in a surprisingly short time.