Deafening Blasts From 6,000-Year-Old Conch Shells Suggest Neolithic Use As Horns

Researchers testing Neolithic conch shells from Catalonia have discovered that these prehistoric objects can produce extraordinarily loud sounds when used as horns. The experiments, conducted by archaeologists Miquel López-García and Margarita Díaz-Andreu of the University of Barcelona, support the idea that people living around 6,000 years ago may have used these shells for long-distance signalling as well as occasional musical expression.

Study and Methods

The team examined 12 large sea-snail shells (Charonia lampas) recovered from five archaeological sites in the lower Llobregat River basin and the pre-coastal depression of the Penedès, east of Barcelona. All 12 shells had their apexes removed, creating a mouth opening suitable for blowing. Several specimens bore biological traces from organisms such as worms and carnivorous mollusks, suggesting the shells were collected after the snails had died and the interior was empty.

Acoustic Tests

Of the 12 shells, eight were sufficiently intact to be tested. López-García — who is also a professional trumpet player — produced sound from all eight. Seven produced peak volumes above 100 decibels (comparable to a motorcycle), and a single blast reached 111.5 dB — in the range of a car horn or chainsaw. In two shells the researchers were able to elicit up to three distinguishable pitches, although higher notes were unstable. Common brass techniques such as hand-stopping or altering lip tension also destabilized the tones.

Evidence and Interpretation

Two shells contained small perforations that were initially suspected to be deliberate finger-holes, but covering those holes produced no measurable change in acoustic output. The researchers therefore concluded the perforations were likely natural. Taken together — the apex removal, the extreme volume, and the post-mortem biological marks — the evidence points to long-distance signalling as the most plausible primary function for these Neolithic shell trumpets. Their capacity for limited pitch modulation means a musical or ritual role cannot be ruled out.

"The shell trumpets are capable of producing high-intensity sounds and would have been highly effective for long-distance communication," López-García says. "However, they are also capable of producing melodies through pitch modulation, so the possibility that these shells were also used as musical instruments with an expressive intention cannot be ruled out."

Context and Caveats

Charonia shell trumpets have been reported elsewhere in prehistory, with some finds dated as far back as 17,000 years, so the Catalonia examples fit a broader pattern of prehistoric use. The study was limited by sample size and the uncertain effects of modern handling, so additional tests on more specimens and contextual analyses would strengthen the conclusions.

The research is published in the journal Antiquity.