聞こえん

can't hear, cannot be heard

→ 聞こえる
聞こえ can be heard, be audible + Negative ending
verb · potential Rare #39,398
can't hear, cannot be heard A colloquial contraction of 聞こえない.
JA: ここでは先生の声が聞こえん。
EN: I can't hear the teacher's voice here.
Conjugation of 聞こえる

聞こえんのですか

Can't you hear me?

— 生きる (1952)

聞こえん

I can't hear you.

— いまを生きる (1989)

ヤツら早く出てこい聞こえん

You guys, get out here—now! Can't you hear me?

— 炎628 (1985)

何も聞こえん

I can't hear a thing.

— 預言者 (2009)