diff --git a/collection-scripts/characterization/bs1534.py b/collection-scripts/characterization/bs1534.py
index 9db1ac4c61e7dbd8e6116b9bc33a87d329b838d6..a7c95bad59ff89726b07f66917a2a62c8c07c408 100644
--- a/collection-scripts/characterization/bs1534.py
+++ b/collection-scripts/characterization/bs1534.py
@@ -5,7 +5,7 @@ import shutil
 from pathlib import Path
 
 PRELIMINARY_SUBSTRINGS = ["s13", "s14", "s15", "s16"]
-PRELIMINARY_PATTERN = re.compile(r"dm[0-9]*a[1-9](s[0-9]*)\.c[0-1][0-9]\.wav")
+PRELIMINARY_PATTERN = re.compile(r"[a-z]m[0-9]*a[1-9](s[0-9]*)\.c[0-1][0-9]\.wav")
 
 
 def repo_root_dir() -> Path:
@@ -25,8 +25,6 @@ def copy_final_items(verbose: bool = False):
         prelim_dir = final_dir / "preliminaries"
         prelim_dir.mkdir(parents=True, exist_ok=True)
 
-        files_copied = 0
-
         for proc_output in exp_dir.glob("proc_output*"):
             condition_dirs = proc_output.glob("c0?")
             for condition_dir in condition_dirs: