user-1: I noticed that when I meditate on breathing, which I've done about as long as the four immeasurables, I tend to nevertheless hear sounds such as a television or sounds outside my house. When I meditate on the four immeasurables, I don't hear the sounds in the environment. I'm not distracted at all unless I get quite tired. 
And is it possible that for me personally, metta provides more concentration? 
I'm especially curious of this subjectivity aspect in Buddhism. Given the focus on empirical evidence promoted by the Buddha, how does one know / deal with aspects of the path that may be different because of one's own mental disposition? More specifically, how would I ascertain if perhaps some aspects of the path are more difficult to me personally, and whether another way of proceeding would be more beneficial? How do I know what is essential, and what is peripheral?

user295: 
And is it possible that for me personally, metta provides more concentration?

When doing breath meditation your mind is relatively more passive where you watch the breath. When doing the four immeasurables your mind is more active contemplating.
Therefore you can maintain your concentration and blocks out distraction as you refocus on different being. 

I'm especially curious of this subjectivity aspect in Buddhism. Given the focus on empirical evidence promoted by the Buddha, how does one know / deal with aspects of the path that may be different because of one's own mental disposition? More specifically, how would I ascertain if perhaps some aspects of the path are more difficult to me personally, and whether another way of proceeding would be more beneficial? How do I know what is essential, and what is peripheral?

This knowledge is only available to the Buddha. But through trial and error, one may find practices hard and some more easy and fruitful.



The Tathagatha Buddha has realized in the exact way how a person’s abilities develop, how they deteriorate, and accordingly their potential to realize the Dhamma. This is His Sixth power.



Source: The Supreme Buddha with His Ten Powers
Also one can use the following as a guide:


The Pali commentaries further provide guidelines for suggesting meditation subjects based on one's general temperament:

Greedy: the ten foulness meditations; or, body contemplation.
Hating: the four brahma-viharas; or, the four color kasinas.
Deluded: mindfulness of breath.
Faithful: the first six recollections.
Intelligent: recollection of marana or Nibbana; the perception of disgust of food; or, the analysis of the four elements.
Speculative: mindfulness of breath.

The six non-color kasinas and the four formless states are suitable for all temperaments.


Kammaṭṭhāna

How do I know what is essential, and what is peripheral?

The dhamma preached by the Buddha does not need anything to be added or taken out. (Svakkhato) Therefore, there is nothing peripheral of not important.

user-1: The meditation where you are hearing the sounds is actually better.  Meditation isn't a removal from the world, it's an openness to it.  Sounds don't disappear, at least not until you've reached an extremely refined state of concentration (think 10+ years of practice, day eight of a ten day retreat where you've sat for 10 hours a day).  For much of our practice, rather than sound disappearing, we are simple less affected by them...or affected by them in a entirely novel way.  What it sounds like to me is that you are ruminating, not meditating.  You are probably getting caught up in a cycle of thoughts that is actually alienating you from the outside world, your breath, even your very self.  It's kind of like driving.  I think we've all experienced those times where get caught up in this kind revelry.  Minutes and miles fly by without us being aware of them.  The same thing can happen on the cushion if we are not careful.
Concentration practice is concentration practice.  It doesn't matter if you are using a kasina, a koan, or a brahmavihara.  Believe it or not, when it comes to concentration, our personal obstacles are nearly as unimportant as the object we take up.  Just keeping bringing your mind back to that object.  Every distraction you recover from is one more repetition that builds your meditation muscles.  The reps are what matter - not your individual temperament.    

-1: <p>I noticed that when I meditate on breathing, which I've done about as long as the four immeasurables, I tend to nevertheless hear sounds such as a television or sounds outside my house. When I meditate on the four immeasurables, I don't hear the sounds in the environment. I'm not distracted at all unless I get quite tired. </p>

<p>And is it possible that for me personally, metta provides more concentration? </p>

<p>I'm especially curious of this <strong>subjectivity</strong> aspect in Buddhism. Given the focus on empirical evidence promoted by the Buddha, <strong>how does one know / deal with aspects of the path that may be different because of one's own mental disposition?</strong> More specifically, <em>how</em> would I ascertain if perhaps some aspects of the path are more difficult to me personally, and whether another way of proceeding would be more beneficial? How do I know what is essential, and what is peripheral?</p>
 295: <blockquote>
  <p>And is it possible that for me personally, metta provides more concentration?</p>
</blockquote>

<p>When doing breath meditation your mind is relatively more passive where you watch the breath. When doing the four immeasurables your mind is more active contemplating.</p>

<p>Therefore you can maintain your concentration and blocks out distraction as you refocus on different being. </p>

<blockquote>
  <p>I'm especially curious of this subjectivity aspect in Buddhism. Given the focus on empirical evidence promoted by the Buddha, how does one know / deal with aspects of the path that may be different because of one's own mental disposition? More specifically, how would I ascertain if perhaps some aspects of the path are more difficult to me personally, and whether another way of proceeding would be more beneficial? How do I know what is essential, and what is peripheral?</p>
</blockquote>

<p>This knowledge is only available to the Buddha. But through trial and error, one may find practices hard and some more easy and fruitful.</p>

<blockquote>
  <blockquote>
    <ol start="6">
    <li>The Tathagatha Buddha has realized in the exact way how a person’s abilities develop, how they deteriorate, and accordingly their potential to realize the Dhamma. This is His Sixth power.</li>
    </ol>
  </blockquote>
</blockquote>

<p>Source: <a href="https://mahamevnawabm.org/supreme-buddha-ten-powers/" rel="nofollow noreferrer">The Supreme Buddha with His Ten Powers</a></p>

<p>Also one can use the following as a guide:</p>

<blockquote>
  <blockquote>
    <p>The Pali commentaries further provide guidelines for suggesting meditation subjects based on one's general temperament:</p>
    
    <ul>
    <li>Greedy: the ten foulness meditations; or, body contemplation.</li>
    <li>Hating: the four brahma-viharas; or, the four color kasinas.</li>
    <li>Deluded: mindfulness of breath.</li>
    <li>Faithful: the first six recollections.</li>
    <li>Intelligent: recollection of marana or Nibbana; the perception of disgust of food; or, the analysis of the four elements.</li>
    <li>Speculative: mindfulness of breath.</li>
    </ul>
    
    <p>The six non-color kasinas and the four formless states are suitable for all temperaments.</p>
  </blockquote>
</blockquote>

<p><a href="https://en.wikipedia.org/wiki/Kamma%E1%B9%AD%E1%B9%ADh%C4%81na" rel="nofollow noreferrer">Kammaṭṭhāna</a></p>

<blockquote>
  <p>How do I know what is essential, and what is peripheral?</p>
</blockquote>

<p>The dhamma preached by the Buddha does not need anything to be added or taken out. (Svakkhato) Therefore, there is nothing peripheral of not important.</p>
 -1: <p>The meditation where you are hearing the sounds is actually better.  Meditation isn't a removal from the world, it's an openness to it.  Sounds don't disappear, at least not until you've reached an extremely refined state of concentration (think 10+ years of practice, day eight of a ten day retreat where you've sat for 10 hours a day).  For much of our practice, rather than sound disappearing, we are simple less affected by them...or affected by them in a entirely novel way.  What it sounds like to me is that you are ruminating, not meditating.  You are probably getting caught up in a cycle of thoughts that is actually alienating you from the outside world, your breath, even your very self.  It's kind of like driving.  I think we've all experienced those times where get caught up in this kind revelry.  Minutes and miles fly by without us being aware of them.  The same thing can happen on the cushion if we are not careful.</p>

<p>Concentration practice is concentration practice.  It doesn't matter if you are using a kasina, a koan, or a brahmavihara.  Believe it or not, when it comes to concentration, our personal obstacles are nearly as unimportant as the object we take up.  Just keeping bringing your mind back to that object.  Every distraction you recover from is one more repetition that builds your meditation muscles.  The reps are what matter - not your individual temperament.    </p>
