The "Plink" (Glowstone) and "Cowbell" (Soul Sand) sounds for the Note Block have a shorter distance range than all the other Note Block sounds.
I was streaming work on my Note Block songs dabbling with the new sounds and when I played back the song the way I would for a recording (the snake-like, zigzag pattern I like to use for my videos keeps all the notes within a 18-21 block distance from me), I noticed that the "Plink" sound would get so quiet that even my watchers were struggling to hear it. After my stream I created a method to test all the sounds and found only the "Cowbell" had the same issue.

What I expected to happen was...:
All the noteblock sounds could be heard from the same long range distance away (48 blocks).
 
What actually happened was...:
Instead, "Plink" and "Cowbell" have at least half as much of a shorter range than the other sounds. 18 blocks away for "Plink" and 22 blocks away for "Cowbell."
 
Steps to Reproduce:
1. Place Glowstone and another block (I used white wool) in an alternating pattern in a straight line (see attached screenshot) until there are 24 Glowstone within the row.
2. Place a note block on every Glowstone block. (tune if desired)
3. Place a repeater on every wool block feeding into the next note block and set them so you can hear each individual note. I found setting it to the 3rd position worked well for me.
4. Place a block and button to the end that you can feed your redstone signal into. (I used pink wool)
5. Stand on the block with the button on it and press the button.
6. Listen to the note sounds and count how many you hear.
7. Swap out Glowstone for Soul Sand and repeat steps 5 and 6.
 
 
I did this for all the note block sounds to check if any others were off and the rest I can usually count up to 23 times the note gets hit.