For the OnePlus 13, 13R, 12 and Nord N30 5G, different apps and call modes use different microphones. First, record a voice note before anything else. Remove the case, hold the phone away from your palm, and repeat the same recording. This is free and it explains a large share of these.
Differential
Likely causes of “OnePlus 13, 13R, 12 and Nord N30 5G microphone is quiet, muffled or not working”, and how to tell them apart
- 1
A case or grip covering a microphone port
What separates it One situation fails and the others are fine — usually speakerphone or video, where a microphone away from the mouth is doing the work. A case with a misaligned cut-out, or a hand across the bottom edge, is enough.
How to confirm Remove the case, hold the phone away from your palm, and repeat the same recording. This is free and it explains a large share of these.
- 2
Lint in the microphone port
What separates it Audio has become progressively quieter or more muffled over months rather than failing suddenly. The ports are small and they live in a pocket.
How to confirm Look into the ports with a bright light. Record a voice note before and after clearing gently with a soft dry brush.
- 3
An app does not have microphone permission
What separates it It fails in one app and works in the voice recorder. Permissions are revoked by updates, by privacy settings and by users who tapped 'don't allow' months ago.
How to confirm Check that app's microphone permission specifically. This is the first thing to check when the failure is app-shaped.
- 4
A Bluetooth accessory is capturing the audio
What separates it Callers cannot hear you and the phone seems fine, with an accessory connected somewhere — often in another room or a car outside. The call's microphone is on the accessory.
How to confirm Disconnect Bluetooth entirely and repeat the call. This is a very common cause of 'nobody can hear me' with no fault anywhere.
- 5
Noise suppression removing the wrong thing
What separates it Voice sounds thin, cut off at the start of words, or drops in and out in a quiet room. Aggressive noise cancellation can misjudge a quiet speaker.
How to confirm Compare a recording in a normal room against one outdoors. Where the phone offers a voice isolation setting, changing it is the test.
- 6
A screen protector over the earpiece microphone
What separates it Calls held to the ear are affected while speakerphone is fine. A protector that covers the top slot muffles the microphone next to it.
How to confirm Check whether the protector's cut-out lines up with the slot.
- 7
The other end of the call
What separates it One person cannot hear you and everyone else can. Call audio has two ends and a network in between.
How to confirm Call someone else, and record a voice note locally. A clean local recording exonerates the phone completely.
Before you touch a setting
Record this first — changing settings destroys the evidence
- Which situations fail and which work: handset call, speakerphone, video recording, voice note, and one specific app. Different microphones serve different situations.
- A voice note recorded locally, which tests the microphone without the network or the other party involved.
- Whether a case, grip or screen protector is fitted, and whether its cut-outs line up.
- Whether any Bluetooth accessory is connected, including ones out of the room.
- Whether the audio is quiet, muffled, cut off at the start of words, or absent — those describe different faults.
- Whether it changed suddenly or degraded over months.
Try in this order
0 of 8 completedRecord a voice note before anything else
ReversibleThis tests the microphone alone, with no network, no other party and no call software involved. A clean local recording exonerates the microphone entirely and moves the whole investigation to the call path or one app.
Map which situations fail
ReversibleHandset call, speakerphone, video, voice note and one app use different microphones in different combinations. One failing while others work is the single most useful fact here — it identifies which microphone, and it rules out the ones that work.
Disconnect every Bluetooth accessory and retry
ReversibleA connected accessory takes the call's microphone with it, including one in another room or a car parked outside. 'Nobody can hear me' with a perfectly working phone is this more often than any hardware fault.
Remove the case and keep your hand off the bottom edge
ReversibleA case with a misaligned cut-out, or a palm across the bottom microphone, is enough to muffle speakerphone and video while a handset call stays fine. Free to test, and it explains a large share of these.
Check the app's microphone permission
ReversiblePermissions are revoked by updates and by privacy settings, and a denial made months ago is invisible now. When the failure is confined to one app, this is the first thing to check and usually the last.
Inspect the ports under a bright light
ReversibleAudio that has become gradually quieter over months rather than failing suddenly is usually lint. Clear it with a soft dry brush — never a pin, never compressed air forced into the port, never liquid — and record the same voice note again to compare.
Test the same call to a different person
ReversibleCall audio has two ends and a network between them. One person unable to hear you while everyone else can is not your phone, and no amount of work on it will change that.
Compare a quiet room against a noisy one
ReversibleAggressive noise suppression can misjudge a quiet speaker and cut the start of words or drop the voice entirely. Where the phone offers a voice isolation setting, changing it and repeating the same recording is the test.
Model-specific
What is true of this model and not of its siblings
- Model scope
- CPH2655 (13), CPH2647 (13R), CPH2581 (12) and CPH2513 (Nord N30 5G), plus regional variants. OnePlus phone; OxygenOS version, region, alert slider/key, charging protocol and carrier certification vary.
- Hardware — OnePlus specs page
- 6.82-inch 120Hz LTPO display (1600/4500 nits), 6,000mAh dual-cell battery, 12/16GB RAM, Snapdragon 8 Elite, 256/512GB storage, 80W SUPERVOOC wired + 50W AIRVOOC wireless charging.
- Tier — flagship (alert slider)
- The flagship OnePlus — top chip, OxygenOS over Android, and the signature alert slider (a physical 3-position switch for ring/vibrate/silent). If ringtones behave oddly, check the alert slider position first; it overrides on-screen sound modes.
- SUPERVOOC fast charging
- Very fast wired SUPERVOOC charging — but it needs the included OnePlus SUPERVOOC charger AND cable to reach full speed; a generic USB-C charger charges it much slower. Wireless charging on this flagship tier.
- OxygenOS
- OxygenOS differences from stock Android are software, not faults. eSIM support varies by region/model.
- Connector
- USB-C. A cable that fits is not necessarily a cable rated for this phone's charging speed — USB-C carries several power profiles and a cable built for data will charge slowly or intermittently while seating perfectly.
- Modem
- 5G capable. In marginal 5G coverage the phone hands repeatedly between 5G and LTE, which costs more battery and generates more heat than settling on either — so the preferred-network setting is a real diagnostic lever rather than a preference.
- Platform
- Android, with a manufacturer interface layer over it. Battery optimization and background-execution restrictions are applied per app and are far more aggressive than on iOS — which is why 'set this app to unrestricted' is a real fix here and has no equivalent elsewhere.
- Symptom boundary
- This record covers OnePlus OnePlus 13, 13R, 12 and Nord N30 5G when it microphone is quiet, muffled or not working. A different symptom on the same hardware, or this symptom on a different OnePlus product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
- !A local voice note is silent or badly distorted with the case off, the ports clear and no accessory connected — that is the microphone hardware.
- !The fault began after liquid exposure and has not improved after several days of drying.
- !The fault began after a drop, which can displace the microphone or its flex connection.
- !Every microphone on the phone fails simultaneously, which points at the audio subsystem rather than one component.
Evidence ledger
Sources behind this answer
Exact questions
Common questions
My OnePlus 13 isn't charging as fast as advertised.+
SUPERVOOC's headline speed needs the OnePlus SUPERVOOC charger and its specific cable — a standard USB-C charger or a third-party cable will charge it at a much lower, ordinary speed. Use the in-box charger and cable, and note a hot phone or a case can throttle charging to protect the battery. Also check that Settings has fast charging enabled. It is not a fault; SUPERVOOC is proprietary and requires the matching brick and cable.