🎧 Audio Puzzle Analyzer

Find hidden messages in mystery-cache recordings. See sound as a waveform or spectrogram, listen in reverse, change speed, isolate a frequency range, detect musical notes and chords, and decode Morse or telephone keypad tones.

Runs locally in your browser — recordings are not uploaded.
1. Load an audio puzzle

Choose MP3, WAV, OGG, M4A or another format your browser supports, or record sound with your microphone.

No recording loaded

2. Waveform

Click the waveform to seek. Choose a start (A) and end (B) below to analyze or export just part of the recording.

WAVEFORM
0:000:000:00
0:00 / 0:00

3. Spectrogram

Quiet
Loud

Bright horizontal lines indicate steady tones; dots and dashes appear as short and long bars. The spectrogram shows the original audio, even when playback filters are active.

FREQUENCY ↑   /   TIME →
0:00No file3,000 Hz ↑

4. Isolate hidden tones

Band-limit playback to help hear messages beneath music or noise. Filters also apply to downloaded processed WAV audio.

WAV export uses A–B, reverse, speed and enabled filters. Maximum exported selection: 3 minutes of original audio.

5. Morse code detector

Find on/off patterns of a constant-frequency beep. For best results, use a clean tone or narrow down its frequency.

Decoded text
—

Load a recording or try the Morse example.

Dot/dash pattern
—
Morse tool ↗

6. Telephone tone decoder (DTMF)

Detect the two simultaneous tones used by phone keypads: digits 0–9, * and # (plus A–D).

Detected keypad sequence
—

Automatic decoding works best with clear keypad tones.

7. Dominant frequencies

Find the strongest sustained frequencies in the selected audio. Tap one to tune the Morse detector or band-pass range.

No frequencies analyzed yet.

Music and voice have many frequencies. Peaks alone do not prove a hidden message.

8. Musical note & chord detector

Find musical notes in a tune, estimate a chord played at the same time, and inspect the notes across a selected passage. Use A–B above to isolate a section of the original recording.

Likely chord / harmony
—
Choose a short section with a held chord for the most reliable result.
Strongest notes detected
No notes analyzed yet.
Frequencies are mapped to the nearest equal-tempered musical note. Detected notes are estimates, especially with voice or noisy recordings.
Piano key guide · highlighted notes

Note timeline

Tracks the strongest pitch at sampled moments of the selected recording. Click a row in the table to jump to that moment. Short notes between analysis frames can be missed.

Load sound and press Detect notes & chords
No notes detected yet. For a demo, try the Melody or Chord example at the top.
TimeNoteFrequencyAction
No note sequence analyzed yet.

Detected chord changes

Estimated from overlapping pitched notes
No chord passages analyzed yet.

Important: chord names are approximate and work best on clean, sustained instruments. Rich harmonics, drums, multiple instruments, and changing chords may produce ambiguous answers. This is audio pitch analysis—not full transcription or perfect instrument separation. Analysis uses original audio, not playback speed or filters.

How to analyze a geocaching audio puzzle

  1. Load or record the sound. A file may contain spoken words, faint beeps, music, telephone tones or a hidden spectrogram message.
  2. Look at the spectrogram. Morse beeps often form horizontal bars. A drawn word or pattern may appear as shapes at different frequencies.
  3. Listen differently. Try slowing playback, reversing it and isolating a frequency range. Select just the suspicious part of the audio.
  4. Detect music. Select a short phrase and use Musical note & chord detector. For chord names, select a single steady harmony rather than a whole song.
  5. Try decoding. Find the tone frequency and run Morse, or use the DTMF decoder for keypad tones. Treat automatic results as clues that may need checking.