"A friend got some vinegar in his ear. Now he…

A pun on “pickled herring” is:

“A friend got some vinegar in his ear. Now he suffers from pickled hearing!”

Forms of the “pickled hearing” joke have been cited in print since at least 1945.

2 April 1945, Minneapolis (MN) Star-Journal, “It’s a Fact” by Halsey Hall, pg. 16, col. 3:
You might credit Mike Casey at Brady’s with repeating the worst “moron story” of the season: the one about the guy who poured vinegar in his ears so he’d have pickled hearing.

10 April 1945, Medford (OR) Mail Tribune, “Ye Smudge Pot” by Arthur Perry, pg. 4, col. 1:
PUN OF THE WEEK
(Pendleton East Oregonian)
The Old Lady in the Jet Bonnet gave herself a vinegar rinse shampoo yesterday. “Some of it trickled into my ear,” she confides, “and I do hope I won’t suffer from pickled hearing.”

5 December 1951, Boston (MA) Daily Globe, “Sitting In On TV: Songs a La (Dog) Carte Whipped Up by Uncle Miltie” by Ted Sahby, pg. 19, col. 1:
THE PUBLISHER seemed reasonably able to control his generous emotions when Berle plugged a third he named: “Since Father Got Vinegar in his Ears, he’s Suffering from Pickled Hearing.”

20 October 1961, Marietta (GA) Daily Journal, “Try and Stop Me” by Bennett Cerf, pg. 11, col. 3:
Terrible thing happened to Zsa Zsa Horntoot the other day. She got some vinegar in her ear. Now she suffers from pickled hearing.

6 December 1973, The Sun (Baltimore, MD), “Sunday Punch,” Magazine, pg. 38, col. 1:
And the lady who spilled vinegar in her ear now suffers from pickled hearing.

Google Books
The Princess Who Wouldn’t Smile
By Roger L. Danchik
Boston, MA: Baker’s Plays
1982
Pg. 14:
FERDINAND. What do you get when you pour vinegar in a person’s ear?
KING. What.
FERDINAND. Pickled hearing.
KING. What?
FERDINAND. Pickled hearing.
KING. What?
FERDINAND. Pickled hearing.
KING. What?

Google Groups: rec.humor
Henry Cate’s Life2.Q
Scott Thurston (ex-zoomie)
7/15/91
(...)
A friend got some vinegar in his ear, now he suffers from pickled hearing.

Google Groups: alt.humor.puns
“Puns of the Weak” 12/15/00
Stan Kegel
12/16/00
(...)
There was this lady who accidentally got some vinegar in her ear, of all places. Now she suffers from pickled hearing. (Syman Hirsch)

Google Groups: alt.humor.puns
Kids Puns of the Weak 01-25-05
Stan Kegel
1/25/05
(...)
A friend got some vinegar in his ear, now he suffers from pickled hearing.

Twitter
Ryan Gravois‏
@Ryan2theG
I friend got vinegar in his ear, now he suffers from pickled hearing.
1:51 PM - 6 Mar 2009

Twitter
Linda Causey‏
@APerfectWorld
Q: What happened when a guy got some vinegar in his ear? A: He suffers from pickled hearing.
10:30 AM - 1 Apr 2009

Google Books
Sensible Nonsense..Frank’s Comic Pack:
Humour Pack Series
By Frank Paul
BookBaby
2014
Pg. ?:
“A friend got some vinegar in his ear, now he suffers from pickled hearing.”

Twitter
Woodmans Food Market‏
@WoodmansFood41
A friend of mine got some vinegar in his ear, now he suffers from pickled hearing! #FoodJokeFriday
11:02 AM - 24 Feb 2017