When we have difficulty listening, the ancient ear muscles become activate again

The New York Times

Listening Effort: The superior auricular muscle responds more when background noise makes speech harder to follow.
These auricular muscles helped change the shape of the pinna, or the shell of the ear, funneling sound to the eardrums.
Similar research has already shown that the largest muscles, posterior and superior auricular muscles, react during attentive listening.
Hearsay The scientists found that the two auricular muscles reacted differently to the different conditions.
The posterior auricular muscles reacted to changes in direction, while the superior auricular muscles reacted to the difficulty level of the task.

POSITIVE

In conclusion, our ancestors’ ability to focus on sounds was aided by vestigial ear muscles in humans. According to recent studies, when we strain to hear in noisy settings, these muscles continue to contract. Auricular muscle activity was measured by researchers using electromyography while participants listened to an audiobook with distracting background noise.

When participants found it difficult to follow speech, the superior auricular muscle reacted the strongest. These minute muscle contractions probably don’t enhance hearing, but they might offer a quantifiable indicator of listening effort. It might be possible to better understand their function in people with hearing impairments with more research.

Key Facts:.

Vestigial Function: When required to listen intently, the human ear muscles that were originally employed to localize sounds continue to contract.

Listening Effort: When background noise makes it difficult to follow speech, the superior auricular muscle reacts more strongly.

Future Research: Gaining an understanding of these muscles could help people with hearing impairments and enhance hearing tests.

Frontiers, the source.

Your ability to move your ears allows you to use the muscles that our distant ancestors used to listen intently. In order to direct sound toward the eardrums, these auricular muscles assisted in reshaping the pinna, or ear shell.

Humans only have vestigial auricular muscles because our ancestors stopped using them millions of years ago. Scientists studying how these muscles work have now found that when we try to listen to competing sounds, they contract.

The first author of the study published in Frontiers in Neuroscience, Andreas Schröer of Saarland University, explained that ear wiggling is facilitated by three major muscles that connect the auricle to the skull and scalp.

During demanding listening tasks, these muscles, especially the superior auricular muscle, become more active. This implies that, particularly in demanding auditory environments, these muscles are used not only as a reflex but also possibly as a component of an attentional effort mechanism. “.”.

pulling your ears out.

Without self-reported measures, it is challenging to assess someone’s listening intensity. Nevertheless, electromyography, which gauges a muscle’s electrical activity, can be used to detect activity in the auricular muscles associated with attentive listening.

The largest muscles, the posterior and superior auricular muscles, have already been demonstrated in similar studies to respond during attentive listening. They are thought to have played a role in moving the pinna in order to record sounds because they pull the ears up and back.

“We don’t know exactly why these became vestigial, because our ancestors lost this ability around 25 million years ago,” Schröer said.

One explanation is that as we improved our visual and vocal systems, the evolutionary pressure to move the ears stopped. “.”.

In order to determine whether these muscles are more active when performing more challenging listening tasks, the researchers gathered 20 individuals without hearing issues. An audiobook and distracting podcasts were played from speakers in front of or behind the participants after electrodes were applied to their auricular muscles.

Three varying degrees of difficulty were covered in twelve five-minute trials for each participant.

The podcast was quieter than the audiobook when it was in easy mode, and the speaker’s voice stood out more than the audiobook did. A podcast that sounded more like the audiobook was added, and the distractions were amplified, to create two more challenging modes.

To ensure that even the most challenging condition could be achieved, the researchers took care to ensure that no physiological effort would be detected if the participants gave up.

After that, the participants were asked to rate their level of effort and estimate how frequently they lost the audiobook’s thread during each trial. The participants were also given a quiz on the subject matter of the audiobook.

Rumor.

The two auricular muscles responded differently to the various conditions, according to the researchers’ findings. Superior auricular muscles responded to task difficulty, whereas posterior auricular muscles responded to direction changes.

As the task became more challenging, participants’ self-reported effort levels and the frequency with which they lost track of the audiobook increased, and between the medium and the difficult mode, their accuracy in answering questions about the audiobook significantly decreased.

The activity levels of the superior auricular muscles were correlated with this: they were highly active during the difficult mode but did not activate more during the medium mode than during the easy mode.

This implies that, while it is unknown whether the superior auricular muscles’ activity aids in hearing, it may offer an objective indicator of listening effort.

“There is probably no discernible benefit because the ear movements that could be produced by the signals we have recorded are so tiny,” Schröer said.

Our capacity to localize sounds is aided by the auricle itself, though. Our auriculomotor system, which has been vestigial for 25 million years, likely makes every effort but fails to produce much. “.”.

To validate these findings and create useful applications, the scientists noted that more research will be required. Their sample, which consisted of young people without hearing issues, was small, as is the case with many hearing studies. It is necessary to have larger, more varied participant groups under more practical circumstances.

“We want to look into the potential effects of muscle strain itself or the tiny movements in the ear on the transmission of sound,” Schröer stated.

It would be intriguing to look into how these factors affect those who have hearing loss. “.”.

Regarding this news about research in auditory neuroscience.

Angharad Brewer Gillham wrote this.

Frontiers is the source.

Get in touch with Frontiers’ Angharad Brewer Gillham.

Image: Neuroscience News is credited with this image.

Original Research: Free to use.

Andreas Schröer and colleagues’ study, “Electromyographic Correlates of Effortful Listening in the Vestigial Auriculomotor System.”. New developments in neuroscience.

Abstract.

Vestigial Auriculomotor System Electromyographic Correlates of Effortful Listening.

Based on a vestigial pinna-orienting system, electromyographic (EMG) signals of the auricular muscles have recently been demonstrated to be a measure of spatial auditory attention in humans.

Since the more general notion of attentional effort in listening is closely linked to spatial auditory attention in a competing speaker task, the current study examined the possibility that the EMG activity of auricular muscles could also reflect correlates of effortful listening in general.

Twenty were enlisted. In a competing speaker paradigm, participants listened to a target podcast while EMG signals from the left and right superior and posterior auricular muscles (SAM, PAM) were recorded.

By altering the quantity and pitch of distractor streams, as well as the signal-to-noise ratio, three distinct conditions were created, each more challenging and requiring more active listening. Every audio stream was either played from a loudspeaker positioned in the back (180°) or in front of the participants (0°).

While averaged PAM activity was not impacted by varying effortful listening levels overall, it was noticeably higher when stimuli were presented from the rear rather than the front.

While the direction of the stimulus had no effect on average SAM activity, the most challenging condition, which demanded the greatest amount of effort, had significantly higher average SAM activity than the easier conditions.

The vestigial pinna-orienting system’s reaction to a demanding stream segregation task is what we interpret as the increased SAM activity.

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