You connect a USB-C charger to your hub.

The laptop starts charging normally.

Then you notice a faint sound:

buzz...

eeeeee...

or a high-pitched electrical whine.

Move your ear closer and it seems to come from the USB-C hub—or perhaps the charger next to it.

Nothing disconnects. Charging still works. But should the noise be there at all?

A faint electronic tone can sometimes be caused by coil whine, where electrical components physically resonate as current changes.

But not every buzzing sound is harmless coil whine.

The first task is to locate the source:

Charger → USB-C Cable → Hub → Laptop

Then observe whether the sound changes with charging load.

Draw a Four-Point Sound Map

Do not start by replacing the hub.

Listen to each point separately.

Move the charger physically away from the hub if the cable allows it.

This matters because a compact charger sitting only a few inches away can easily sound as though the hub itself is making the noise.

Once you identify the loudest point, the troubleshooting path becomes much clearer.

First Separate Coil Whine From Audio Noise

This article is about physical sound coming from the hardware.

It is not about:

• buzzing through headphones;
• microphone static;
• crackling speakers;
• USB audio interference.

To test this, mute the laptop completely.

Disconnect headphones and speakers.

If you can still hear the sound directly from:

charger / hub / laptop chassis

you are dealing with physical electrical noise rather than an audio-output problem.

A faint high-frequency tone that changes with electrical load can be consistent with coil whine. Lenovo's explanation of why coil whine occurs in electronic devices describes it as audible vibration from electromagnetic components when current passes through them. Lenovo also notes that coil whine can be an acoustic characteristic rather than automatically indicating a hardware defect.

That does not mean every buzzing USB-C hub should automatically be considered normal.

You still need to check what happens as the power load changes.

Use a Power-Load Ladder

Instead of randomly connecting and disconnecting accessories, increase the load gradually.

Level 1 — Charger Alone

Disconnect the USB-C hub.

Leave only:

Wall Outlet → Charger

Listen carefully.

Charger already makes the same noise

The hub is probably not the original source.

Try another known-compatible charger before troubleshooting the hub.

Charger is silent

Move to the next level.

Level 2 — Charger + Empty Hub

Connect:

Charger → Hub PD Port

and:

Hub → Laptop

Remove:

• SSDs;
• phones;
• HDMI;
• card readers;
• webcams;
• other USB devices.

Now listen again.

Noise appears immediately

The sound is associated with the PD charging path even before peripherals are added.

Possible areas include:

charger + PD negotiation + hub power-conversion electronics + laptop load

Do not assume the hub alone is responsible yet.

Level 3 — Change the Laptop Charging Load

Observe the sound when the laptop battery is:

low

versus:

nearly full

and when the laptop is:

idle

versus:

doing heavier work.

Does the pitch change?

Does it disappear under higher load?

Does it become more noticeable when the computer is almost fully charged?

These changes can be useful because power-conversion circuits operate differently as electrical load changes.

ASUS also notes in its explanation of high-frequency electronic noise and coil whine that changing electrical current can cause components to resonate at audible frequencies.

A changing pitch that follows power load is therefore more consistent with an electrical-resonance phenomenon than with a loose fan or ordinary speaker noise.

Level 4 — Add Peripherals One at a Time

Once the empty hub is stable, reconnect:

Keyboard / Mouse

→ HDMI Monitor

→ External SSD

→ Webcam

→ Phone

Listen after each step.

Suppose the hub is nearly silent until an external SSD is added.

Then:

SSD connected → whine appears

SSD removed → whine disappears

That does not necessarily mean the SSD is defective.

The additional peripheral changes the hub's total electrical load.

Likewise, plugging in a phone may change how the hub distributes available power.

The useful clue is:

Which change causes the sound to begin or change pitch?

Understand What USB Power Delivery Is Doing

A USB-C PD charging setup is not simply a fixed-voltage cable.

Compatible devices communicate to determine supported power roles and operating levels.

The USB Implementers Forum's current USB Power Delivery specification defines the standards used for USB-C power negotiation between compatible sources and sinks.

A typical charging path is:

PD Charger

↓

USB-C Hub

↓

Laptop

The hub also needs power for its own electronics and connected peripherals.

So the electrical load can change when you:

• connect the charger;
• plug in the laptop;
• add an SSD;
• start HDMI output;
• connect a phone;
• increase laptop workload.

Those load changes can alter the acoustic behavior of power-conversion components.

Do Not Confuse “100W PD” With Constant 100W Load

A hub labeled 100W PD is not continuously pulling or delivering exactly 100W.

The actual power depends on:

• charger capability;
• cable rating;
• laptop charging limit;
• battery state;
• hub overhead;
• attached devices.

If you're trying to understand why the noise changes as devices are added, the guide explaining why a 100W USB-C hub may deliver less than the charger's full rated wattage provides the relevant power-budget background.

This also explains why the acoustic behavior can change without anything being physically moved.

The electrical load itself changed.

What a Typical Coil-Whine Pattern Looks Like

A possible coil-whine pattern is:

faint

high-pitched

changes with power load

easier to hear in a quiet room

no charging interruptions

no burning smell

no excessive heat

no visible damage

This combination is very different from an unstable or unsafe power connection.

For example:

Low battery → faint whine
Heavy charging → different pitch
Battery nearly full → tone changes again

That load-sensitive behavior is useful evidence.

However, you cannot confirm electrical safety by sound alone.

When the Sound Is NOT Something to Ignore

Stop using the setup and disconnect power if the buzzing is accompanied by:

• burning smell;
• visible smoke;
• sparks;
• melted or discolored connector;
• repeated crackling;
• charger or hub becoming abnormally hot very quickly;
• damaged cable;
• charging repeatedly cutting in and out.

A faint high-frequency tone and electrical arcing/crackling are not the same symptom.

Do not open the charger or hub to inspect internal components.

If there is visible damage, burning odor, sparking, or persistent abnormal behavior, replace or service the affected hardware.

If the issue is instead:

charging → stops → starts → stops

use the dedicated guide for a USB-C charger that keeps connecting and disconnecting through a hub.

That is a PD stability problem, not simply an acoustic-noise problem.

Check Temperature Separately

Electrical noise and heat can happen at the same time, but they are not the same diagnosis.

A hub handling:

PD charging

HDMI

external SSD

and:

multiple USB devices

can naturally become warmer under load.

But if you notice:

buzzing + rapidly rising temperature + repeated resets

the combination deserves more attention.

Use the separate guide explaining when a warm USB-C hub becomes an overheating concern rather than treating temperature as proof of coil whine.

A slightly warm aluminum enclosure is one thing.

A unit that becomes difficult to touch, smells unusual, or repeatedly disconnects is another.

Swap the Charger Before You Swap the Hub

If the noise occurs only when PD charging is active, change one upstream variable.

Use another:

reputable, compatible USB-C PD charger

with sufficient wattage for the laptop.

Keep the same:

• hub;
• laptop;
• peripherals;
• wall outlet if possible.

Noise disappears

The original charger or the interaction between that charger and the rest of the PD chain was likely part of the acoustic behavior.

Noise remains at the hub

Now repeat the test with another compatible charging cable.

This lets you narrow:

Charger

→ Cable

→ Hub

instead of replacing everything at once.

Connection Order Can Also Be a Clue

Try:

Charger → Hub → Laptop

and compare it with:

Hub → Laptop → Charger

If the noise is accompanied by unstable charging or only one connection order works reliably, you may be looking at a PD negotiation issue rather than ordinary coil whine.

The separate guide on a USB-C hub that charges only in a certain connection order explains that PD handshake scenario in more detail.

A faint noise that changes pitch is one problem.

A hub that needs a precise plug-in ritual to remain powered is a different one.

When a Clearer Power/Data Layout Helps

Changing the hub cannot guarantee complete silence because coil whine can depend on the entire charger–hub–laptop combination.

However, if you're redesigning a desk after troubleshooting, clearly separated charging and data roles can make future diagnosis easier.

For a setup focused on USB-C storage and peripherals, a USB-C hub with four 10Gbps USB-C data ports and a separate 100W PD input keeps high-speed data connections distinct from the charging input.

The LENTION CE31s provides four USB-C USB 3.2 Gen 2 data ports and up to 100W PD pass-through, with its downstream USB-C ports explicitly designated for data rather than charging or video.

That means a troubleshooting setup can clearly separate:

PD Charger → PD Input

from:

SSD / USB Device → Data Port

which reduces confusion about which USB-C connector is handling power.

For a more complete desk with display output, storage, and peripherals, a 6-in-1 USB-C hub with 4K@60Hz HDMI, four data ports, and 100W PD provides a different mixed-workstation layout.

The LENTION CB-CE35p combines 100W PD input, 4K@60Hz HDMI, three USB-A data ports, and one USB-C data port.

Neither model should be described as:

“a coil-whine fix.”

The important benefit here is a clearly specified power and port layout for building a predictable charging setup.

Read the Sound Pattern Like This

The goal is not to label every sound.

It is to identify the condition that produces it.

Quick Answers

Why does my USB-C hub make a high-pitched noise while charging?

Electrical components involved in power conversion can physically resonate as current changes, producing an audible high-frequency tone commonly called coil whine.

Does a buzzing hub mean it is defective?

Not automatically. A faint load-sensitive electronic tone can occur without a hardware failure, but buzzing accompanied by instability, extreme heat, burning smell, sparks, or visible damage should not be ignored.

Why does the sound change when my laptop reaches 100% battery?

The charging load changes as the battery and system power requirements change, which can alter the behavior of power-conversion components.

Why does plugging in an SSD make the noise louder?

The SSD adds electrical load to the hub and can change the total power demand. That can change the pitch or intensity of load-sensitive electrical noise.

Can a different charger stop the noise?

Sometimes. Because the charger is part of the same PD power chain, changing to another compatible charger can change or eliminate the acoustic behavior.

Is this the same as buzzing in my headphones?

No. Physical coil whine comes from electronic hardware itself. Headphone or speaker buzzing belongs to the audio signal path.

Final Takeaway

If your USB-C hub makes a buzzing or high-pitched noise while charging, do not begin by assuming:

Hub = defective.

Map the sound source first:

Charger

→ Cable

→ Hub

→ Laptop

Then change the electrical load gradually:

Charger Alone

→ Empty Hub

→ Laptop Charging

→ Add Peripherals

The key distinction is:

A faint high-frequency tone that changes with electrical load can be consistent with coil whine, while crackling, burning smells, sparks, excessive heat, or repeated power resets require a different—and more cautious—response.

And remember:

USB Power Delivery changes the electrical load dynamically, so the sound can change even when the physical setup stays the same.

Once you know where the sound comes from and what load makes it appear, you can decide whether you're hearing a benign acoustic characteristic, a charger/hub interaction, or a genuine charging problem that needs hardware attention.