The samples used in Bomberman II (or Dynablaster in Europe) were recently discovered to be corrupted due to an encoding issue known as bit reversal. This hack restores said samples to their original glory.
The patch works for all 3 versions (JP, USA, EU) of the game. You will need an IPS patch installer to patch the rom such as
http://www.romhacking.net/utilities/240/.
Database match: Bomberman II (Japan)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: 05FF785674AA79B80F0C8D0365D66A0DE088BCB2
File CRC32: DE808339
ROM SHA-1: CD665ACEA15A4542A9E4CF16A7CA2CE53C88726D
ROM CRC32: C401790
Database match: Bomberman II (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: DBBF5F7293E2D14EB8C3BA8ABC7E1D2F967F9C2B
File CRC32: CC7BCFEB
ROM SHA-1: 2E401097B7B6F5DE5B0F88E6A97C5675BD916801
ROM CRC32: 1EBB5B42
Database match: Dynablaster (Europe)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: 58EDD4BB692191C1BAC79D0B8B4CA1D6F6EB9305
File CRC32: E67BE1D2
ROM SHA-1: 31C720F9A75EB2D069244BD257AA23DE6B5BCE8B
ROM CRC32: 34BB757B