simil telefono

convert.sh

#!/usr/bin/env bash
set -euo pipefail
shopt -s nullglob

for f in *.wav; do
  echo "[*] $f"
  sox --clobber "$f" -C 48 -r 8000 -c 1 "${f%.wav}.mp3" \
      highpass 300 lowpass 3400 \
      compand 0.02,0.20 6:-80,-60,-40,-30,-20 -6 -90 0.2 \
      gain -n -1 dither -s
done