The short answer
Clean the socket first, because compacted lint prevents the plug seating fully and produces exactly this symptom. Then twist and flex the cable near the plug while listening: if the sound changes, the cable has failed internally, which is the most common wired headphone fault and not repairable in practice.
Wired audio has very few components, which makes diagnosis straightforward. Sound reaches the driver through a cable, a plug, a socket and a small amplifier. Crackling, one-sided sound or intermittent audio comes from one of those four, and you can identify which in a couple of minutes.
Step 1: split headphones from device
Try the headphones on another device
If the fault follows the headphones, it is the cable, plug or driver. If it stays with the phone or laptop, it is the socket or the software.
Try different headphones on the original device
The other half of the same test, and together they settle the question.
Flex the cable at the plug while listening
Bend it gently through about 45 degrees and rotate it. Crackling or dropouts that follow the movement confirm a broken conductor inside, almost always within a few centimetres of the plug.
Flex the cable where it enters the earpiece
The second most common failure point, particularly on in-ear headphones.
Wiggle the plug in the socket
If the sound changes with slight pressure, either the plug is not seated fully or the socket contacts are worn.
Step 2: clean the socket
A phone’s headphone socket, where one exists, is a pocket-facing hole that collects lint just as the charging port does. Compacted debris stops the plug reaching the bottom, which leaves one contact ring misaligned and produces one-sided or crackling sound.
- Power the device off.
- Look inside with a light and magnification.
- Use a wooden or plastic toothpick, gently, scraping along the side wall and lifting material out.
- Avoid metal, which can bridge contacts or scratch them.
- Finish with a short burst of air and test whether the plug now clicks in fully.
A plug that used to click in and now stops slightly short is almost certainly sitting on a plug of lint.
Do not spray contact cleaner or any liquid into a headphone socket on a phone. The socket sits close to other components and phones are not designed for it. Dry removal is slower and does not risk a larger repair.
Step 3: the adapter, if you use one
Most phones no longer have a headphone socket, so the audio path includes a USB-C or Lightning adapter containing a small digital to analogue converter. Adapters are a common failure point:
- They are small, carried loose, and flex at both ends.
- Cheap ones use poor converters that hiss and crackle from new.
- Some are device-specific and behave unpredictably on other phones.
- The USB-C port itself collects lint, producing an intermittent connection.
Test with a different adapter before concluding anything about the headphones or the phone. This single test resolves a large share of cases.
Step 4: software causes
- The phone thinks headphones are still connected after unplugging, usually due to debris in the socket. Cleaning fixes it; restarting is a temporary workaround.
- Audio enhancements or equalisers clipping the signal, which sounds like crackling at higher volumes.
- Volume limits and accessibility balance settings, which explain one-sided sound with no hardware fault at all.
- A specific app, which is worth testing against another before blaming hardware.
Check the audio balance slider in accessibility settings. It is easy to knock and it produces exactly the symptom people interpret as a failed driver.
Step 5: the headphones themselves
If the fault follows the headphones and does not respond to cable movement, the driver or its internal connection has failed. On most consumer headphones this is not economically repairable, and on models with detachable cables it often is, because the cable is the usual culprit and a replacement costs little.
That is a strong argument for buying headphones with detachable cables: the single most common failure becomes a cheap part rather than a new pair.
Preventing it
- Unplug by the plug, never by pulling the cable.
- Do not wrap the cable tightly around the device, which stresses it exactly where it fails.
- Use a loose over-under coil rather than a tight wrap.
- Keep the socket and the port clean, checking every few months.
- Do not leave headphones plugged in inside a bag, where the plug acts as a lever.
Why do I only hear sound in one ear?
Usually the plug is not fully seated, because of lint in the socket, or a conductor in the cable has broken near the plug. Clean the socket first, then test by flexing the cable.
Can I repair a broken headphone cable?
With detachable cables, replace it and the problem is solved cheaply. With fixed cables, a repair means cutting and resoldering near the plug, which is possible and rarely worth the effort on inexpensive headphones.
Why does my phone think headphones are plugged in?
Debris in the socket bridging the detection contact. Clean it carefully with a wooden toothpick, and restart the phone afterwards to clear the stuck state.
Are USB-C headphone adapters unreliable?
They are a common failure point because they are small, carried loose and flex at both ends. Keeping a spare is sensible, and testing with a second one is the fastest diagnostic.
Why do cheap adapters hiss?
They contain a small digital to analogue converter, and inexpensive implementations have a higher noise floor. A better adapter genuinely sounds cleaner, which is one of the few places where spending more is audible.
The order
Test the headphones on another device and another pair on yours, which settles where the fault lives. Clean the socket or the port with a wooden toothpick. Flex the cable at the plug and at the earpiece while listening. Swap the adapter if you use one. Check the accessibility balance slider before assuming a driver has failed.
