PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Koalas' low-pitched voice explained by unique organ

2013-12-02
(Press-News.org) Contact information: Mary Beth O'Leary
moleary@cell.com
617-397-2802
Cell Press
Koalas' low-pitched voice explained by unique organ

VIDEO: This video shows the velar fold vibration at 10-45 Hz.
Click here for more information.

The pitch of male koalas' mating calls is about 20 times lower than it should be, given the Australian marsupial's relatively small size. Now, researchers reporting in the Cell Press journal Current Biology on December 2 have discovered their secret: koalas have a specialized sound-producing organ that has never before been seen in any other land-dwelling mammal. The key feature of this newly described organ is its location outside the voice box, what scientists call the larynx.

"We have discovered that koalas possess an extra pair of vocal folds that are located outside the larynx, where the oral and nasal cavities connect," says Benjamin Charlton of the University of Sussex. "We also demonstrated that koalas use these additional vocal folds to produce their extremely low-pitched mating calls."

AUDIO: This is a sound file of a koala bellow.
Click here for more information.

The koala's bellow calls are produced as a continuous series of sounds on inhalation and exhalation, similar to a donkey's braying, Charlton explains. On inhalation, koala bellows sound a bit like snoring. As the animals exhale, the sound is more reminiscent of belching. And, as Charlton says, "they are actually quite loud."

They are also incredibly low-pitched, more typical of an animal the size of an elephant. Size is related to pitch in that the dimensions of the laryngeal vocal folds normally constrain the lowest frequency that an animal can generate. As a result, smaller species will typically give calls with higher frequencies than larger ones.

Koalas have bypassed that constraint by putting those vocal folds in a new location. Charlton describes the folds as two long, fleshy lips in the soft palette, just above the larynx at the junction between the oral and nasal cavities. They may not look all that different from the laryngeal vocal folds of other mammals, but their location is highly unusual.

"To our knowledge, the only other example of a specialized sound-producing organ in mammals that is independent of the larynx are the phonic lips that toothed whales use to generate echolocation clicks," Charlton says.

The combination of morphological, video, and acoustic data in the new study represents the first evidence in a terrestrial mammal of an organ other than the larynx that is dedicated to sound production. Charlton says that he and his colleagues will now look more closely at other mammals to find out whether this vocal adaptation is truly unique to koalas.



INFORMATION:

Current Biology, Charlton et al.: "Koalas use a novel vocal organ to produce unusually low-pitched mating calls"



ELSE PRESS RELEASES FROM THIS DATE:

Microplastics make marine worms sick

2013-12-02
Microplastics make marine worms sick Tiny bits of plastic trash could spell big trouble for marine life, starting with the worms, say a team of researchers from Plymouth University and the University of Exeter who report their evidence in a pair of studies in the Cell Press ...

JCI early table of contents for Dec. 2, 2013

2013-12-02
JCI early table of contents for Dec. 2, 2013 Predicting outcome for high-dose IL-2 therapy in cancer patients One of the most potent forms of immunotherapy for patients with metastatic melanoma and renal cell carcinoma is high-dose (HD) bolus IL-2 therapy. ...

Predicting outcome for high-dose IL-2 therapy in cancer patients

2013-12-02
Predicting outcome for high-dose IL-2 therapy in cancer patients One of the most potent forms of immunotherapy for patients with metastatic melanoma and renal cell carcinoma is high-dose (HD) bolus IL-2 therapy. Approximately 15% of patients respond to ...

Blocking antioxidants in cancer cells reduces tumor growth in mice

2013-12-02
Blocking antioxidants in cancer cells reduces tumor growth in mice Many cancers have adapted to cope with high levels of immune system-produced free radicals, also referred to as reactive oxygen species, by overproducing antioxidant proteins. One of these ...

Silent RNAs express themselves in ALS disease

2013-12-02
Silent RNAs express themselves in ALS disease RNA molecules, used by cells to make proteins, are generally thought to be "silent" when stowed in cytoplasmic granules. But a protein mutated in some ALS patients forms granules that permit translation of ...

First Nations adults have more than double the risk of end-stage kidney disease

2013-12-02
First Nations adults have more than double the risk of end-stage kidney disease First Nations adults with diabetes have more than double the risk of end-stage kidney disease compared with non–First Nations adults, found a new study in CMAJ (Canadian ...

Johns Hopkins researchers show how a modified pacemaker strengthens failing hearts

2013-12-02
Johns Hopkins researchers show how a modified pacemaker strengthens failing hearts Findings advance opportunities for a 'pacemaker in a bottle' Johns Hopkins heart researchers are unraveling the mystery of how a modified pacemaker used to treat many patients ...

Evolution, Civil War history entwine in plant fossil with a tragic past

2013-12-02
Evolution, Civil War history entwine in plant fossil with a tragic past Union Army forced freed slaves to dig canal where 120 million-year-old fossil plant was found COLLEGE PARK, Md – A fossil leaf fragment collected decades ago on a Virginia canal bank has been identified ...

Key found to restoring 'exhausted' HIV-fighting immune cells

2013-12-02
Key found to restoring 'exhausted' HIV-fighting immune cells Protein could prove a promising new drug target Researchers have identified a protein that causes loss of function in immune cells combatting HIV. The scientists report in a paper appearing online Dec. 2 in ...

New evidence that 'gout' strongly runs in the family

2013-12-02
New evidence that 'gout' strongly runs in the family It's historically known as 'the king of diseases and the disease of kings' and was long thought to be caused by an overindulgent lifestyle, but now scientists at The University of Nottingham have confirmed ...

LAST 30 PRESS RELEASES:

Gemini South aids in discovery of elusive cloud-forming chemical on ancient brown dwarf

UIC researchers awarded $8.3M federal grant to study alcohol use disorder

NCCN Policy Summit explores whether artificial intelligence can transform cancer care safely and fairly

Mitcham receives funding to strengthen food as medicine pathways in southwest Virginia

PCORI awards new patient-centered CER to support informed health care decisions

Global integration of traditional and modern medicine: policy developments, regulatory frameworks, and clinical integration model

How to find a cryptic animal: Recording the elusive beaked whale in the Foz do Amazonas Basin

Long COVID and food insecurity in US adults, 2022-2023

Bariatric surgery and incident development of obesity-related comorbidities

Microbiome instability linked to poor growth in kids

Can a healthy gut microbiome help prevent childhood stunting?

Achieving low resistance and high performance in MTJs using high-entropy oxides

Gut microbiome influences proteins that drive aging and disease

NIH funds first-of-its-kind center to study resilience and aging

Mesonephric carcinoma and mesonephric-like adenocarcinoma of the female genital tract

Rural patients in the United States still face barriers to telehealth access

Emphysema at CT lung screening increases death risk in asymptomatic adults

Brain iron on MRI predicts cognitive impairment, decline

The ISSCR partners with Nuffield Council on Bioethics to compile global horizon scan on stem cell research

Machine learning unveils COPD patient clusters and quality of life associations in China

No sign of toxic effects of inhaled anesthesia in young children

CUNY SPH expands curriculum with concentration in sexual and reproductive justice and health

High consumption of ultra-processed foods linked to systemic inflammation

City of Hope launches transformative national clinical trials model to accelerate cancer research

Inside an academic scandal: a story of fraud and betrayal

Innovative ultrasonic regeneration restores nano-phase change emulsions for low-temperature applications

Targeted snow monitoring at hotspots outperforms basin-wide surveys in predicting water supply

Decades-old barrels of industrial waste still impacting ocean floor off Los Angeles

Finalists announced for the 2025 Blavatnik National Awards for Young Scientists

Alkali waste dumped in the Pacific Ocean created alkalophilic ecosystems

[Press-News.org] Koalas' low-pitched voice explained by unique organ