Mosquito Noise: Friend Or Foe For Studio Monitors?

Mosquito noise is a colourful name for a problem that can occur in digital television pictures, whether HD or 4K. It is a compression artifact that arises when broadcasters, cable or satellite companies send out a compressed signal to fit all desired channels into the stream. This compression involves a lot of math and therefore the possibility of intentional errors. Mosquito noise occurs wherever there are sharp colour contrasts, with little bits of one colour showing up where they shouldn't, like mosquitos swarming around the image's subject. While there is not a lot that can be done to eradicate mosquito noise, it can be minimised with proper calibration and by turning down the sharpness of the picture.

What is mosquito noise?

Mosquito noise refers to a specific type of audio distortion that occurs in digital video and audio compression. It is a type of artefact or unwanted side effect that appears near the crisp edges of objects in MPEG and other video frames that are compressed with the discrete cosine transform (DCT).

This noise occurs during decompression when the decoding engine approximates discarded data by inverting the transform model. It appears as random aliasing in these areas and can be challenging to eliminate, requiring sophisticated detection circuits. As TV screens and monitors get larger, mosquito noise becomes more noticeable.

The term "mosquito noise" is also used to describe a high-frequency sound that is inaudible to adults but can be heard by teenagers and younger individuals. This sound, produced at a frequency of around 17.4 kHz, is used in security products to repel loitering teenagers. It is effective because, as humans age, their ability to hear higher frequencies decreases, a phenomenon known as presbycusis.

While the mosquito noise in audio and video compression may not be desirable, the mosquito tone used in security systems serves a specific purpose: to create a high-pitched sound that is uncomfortable for younger individuals but inaudible to adults.

What causes mosquito noise?

Mosquito noise is caused by the rapid movement of a mosquito's wings during flight. The mosquito's unique anatomy, including its wing movement, frequency, and vibrations, creates this high-pitched buzzing sound. The frequency of the buzzing noise is determined by the wing beat frequency, which varies between species and can range from 300 to 600 beats per second. Additionally, smaller mosquitoes tend to produce higher-pitched sounds.

The buzzing sound is a form of communication between male and female mosquitoes during the mating process. Female mosquitoes produce a lower-pitched frequency that attracts male mosquitoes. During mating, the buzzing sound from both males and females becomes more intense and frequent.

The mosquito's buzzing sound can be heard by humans and other animals. This sound can be particularly noticeable near our ears, as mosquitoes are attracted to the carbon dioxide we exhale when we breathe. Our ears, being close to our noses and mouths, are naturally within the range of this attraction.

While the buzzing noise may seem like an irritating nuisance, it serves an important purpose for mosquitoes. It helps them navigate, communicate, and find potential mates.

In addition to the natural mosquito noise, there is also a term called "mosquito noise" or "mosquito tone" in audio and video technology. This refers to a distortion that appears near crisp edges of objects in MPEG and other video frames that are compressed with the discrete cosine transform (DCT). This type of mosquito noise is not related to the buzzing sound produced by mosquitoes but is instead an artifact of digital compression.

How does mosquito noise affect studio monitors?

Mosquito noise is a form of distortion that appears near the crisp edges of objects in MPEG and other video frames that are compressed with the discrete cosine transform (DCT). It occurs during decompression when the decoding engine approximates discarded data by inverting the transform model.

The noise appears as random aliasing and requires sophisticated detection circuits for its elimination. As TV screens get larger, mosquito noise and similar artifacts become more noticeable.

Mosquito noise is one of several problems that can affect an otherwise pristine television picture, whether it's HD, 4K, or standard definition. It is caused by the compression of video files, which is necessary to reduce the amount of data being transferred. This compression introduces "intentional errors" into the data, which can cause flaws in the decompressed image or video.

These flaws are more noticeable when the sharpness of the image is increased, and they tend to swarm around the image's subject, giving the effect of being surrounded by mosquitos.

To reduce the impact of mosquito noise, proper calibration of the display is essential. Additionally, lowering the sharpness of the image may help to hide the noise, as an oversharpened picture will accentuate flaws.

In terms of studio monitors, mosquito noise can be considered a form of digital distortion, which is characterised by "grinding" or "buzzing" sounds that appear unnatural. Digital distortion is typically caused by issues with the audio interface or by connecting the monitors to the same power source as the computer.

To mitigate digital distortion, it is recommended to use a separate power source for the monitors and the computer. Alternatively, a quality power conditioner can be employed to reduce noise in the line.

How to reduce mosquito noise?

The mosquito noise is a form of distortion that appears near the crisp edges of objects in MPEG and other video frames that are compressed with the discrete cosine transform (DCT). It occurs during decompression when the decoding engine approximates discarded data by inverting the transform model.

To reduce mosquito noise, you can use sophisticated detection circuits to eliminate it. Algolith's Home Theatre 3D Mosquito Noise Reducer is one such appliance that can be used to remove mosquito noise.

If you are experiencing mosquito noise in your studio monitors, it could be due to a ground loop issue. To overcome this, try isolating the PC mains supply and ensure that the connections are balanced. If the connections are already balanced, try cutting the ground line between the interface and speaker inputs.

Additionally, ensure that your studio equipment is plugged into a separate power supply from your PC. You may also want to consider investing in a higher-end audio interface, as some lower-end devices may have issues with digital noise.

It is important to note that loud sounds, including mosquito noise, can cause equipment and hearing damage, even with brief exposure. Always ensure that your audio system's volume is at a reasonable level.

How to prevent mosquito noise?

Mosquito noise is a form of distortion that appears near the crisp edges of objects in MPEG and other video frames that are compressed with the discrete cosine transform (DCT). It occurs during decompression when the decoding engine approximates discarded data by inverting the transform model. This noise appears as random aliasing and can be difficult to eliminate, requiring sophisticated detection circuits.

To prevent mosquito noise, you can take the following steps:

• Use a larger TV or display: As screen sizes increase, mosquito noise and other artifacts become more noticeable, so using a larger display can help identify and address the issue.
• Employ a noise-reduction appliance: Specialized appliances, such as the Algolith's Home Theater 3D Mosquito Noise Reducer, can be used to minimize mosquito noise.
• Ensure balanced connections: Confirm that your devices have balanced inputs and outputs, as imbalanced connections can lead to ground loop issues and digital noise.
• Isolate power sources: Connect your audio interface and computer to separate power supplies to reduce the possibility of electrical interference causing noise.
• Upgrade your audio interface: Investing in a higher-end audio interface can provide better noise handling capabilities and improve overall sound quality.
• Consult a technician: If you are unsure about the safety of your setup, consider consulting a qualified technician to advise on safe and effective solutions.

Additionally, it is worth noting that the term "mosquito noise" is also used to describe high-frequency tones designed to repel mosquitoes or disperse loitering teenagers. This usage is unrelated to studio monitors, but it is important to be aware of the different contexts in which the term is used.

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