Distortion on human voices but not music [duplicate]

I bought a Dell Inspiron N4110, the sound plays fine from the speaker, but when I plug my earphone (which has the 4-segment TRRS jack, i.e. stereo+mic) then human speech gets distorted although background music tends to play fine this causes speech to get drowned in the music (in movies this means I can't hear what they were talking despite my ear getting hurt by the loud background music).

I tried multiple different video, they're all exhibiting the same symptom, the earphone somehow can distinguish human voice and background music and filter out only those human voices in all the videos I tried.

I tried using a different earphone (a 3-segment TRS jack, i.e. stereo), and this plays fine.

It wasn't the TRRS earphone either, as I regularly use it with my mobile phone fine.

So my guess is that the distortion is because I'm plugging TRRS jack into a TRS socket and they doesn't work well together.

The question is:

1. is there any workaround to use a TRRS earphone on a TRS socket without distortion (I don't need to use the mic)?
2. (bonus) why is it distorting only on human voices?

This is partly taken from my answer here:

Bad sound quality of 3.5mm headphone with mic on laptop

The problem is that when I connect headphone to my Dell N5010 laptop to listen to music, the quality is horrible, with very weak or no vocals.

My answer:

The thing is: Your phone will fit the TRRS jack. Your laptop however probably won't - it could be that one of the stereo rings doesn't match the laptop's output jack perfectly. The laptop will only have two internal connectors (for stereo), whereas the jack has three. The stereo ones will have to overlap exactly.

So, you asked:

is there any workaround to use a TRRS earphone on a TRS socket without distortion (I don't need to use the mic)?

Unfortunately, not really. You might want to look for a TRRS to TRS converter, but they are really rare. Or get some other earplugs with normal TRS connectors.

(bonus) why is it distorting only on human voices?

That's easy. Contemporary music is mixed the following way:

• Vocals should be up front to the listener. They should sound like they are in your head, which is why they are often mixed centered. This means, the vocal signal from a left speaker/headphone is (almost) exactly the same as the vocal signal from the right speaker/headphone.

• Instruments like guitars, synthesizers and drums should sound very spacious and therefore are mixed using stereo to its full extent. In order to perceive a stereo effect, the signal for left and right speakers/headphones must be different.

Now because the TRRS is shaped differently than the TRS, the ground contact in the laptop's TRS jack might overlap with the microphone contact of the TRRS earset. That's why you'll hear the common parts of the stereo signal canceling each other out (i.e. the vocals).

I had exactly this problem (vocals almost gone, music more or less unaffected, especially in the bass area). It was caused by shorted headphone cabling, which was shorting the L/R channels together, which causes the effect per slhck's explanation, but by a different mechanism.

In short, if nothing else works, check the cabling and the internal wiring if you can get to it. Continuity testing between the left and right channels (rings) on the jack would pick up a L/R fault (should be open circuit).

Generally, 4-conductor 3.5mm plugs work fine in 3-conductor jacks. The microphone is supposed to short, which leaves the headphones free to play.

Are you sure that the speakers in your earphones aren't blown? Often, distorted human voices are a telltale sign of blown speakers.

I solved this exact problem by switching the balance L/R to 40/60, instantly sorted it!