No Whistle Sound in Firefox: Check Playback and Frequency

In Firefox, open onlinedogwhistle.com in the visible tab and press its playback control directly. Start with low system volume, nonzero app gain, and a brief steady tone at 440 Hz. If that works but a high preset stays silent, the speaker may not reproduce that frequency. Raising volume is not a useful way to prove otherwise.

Start with a direct press in the visible tab

Bring the Firefox page to the front before checking sound. Browser audio can require a user action, so use the page control directly instead of expecting playback immediately after loading. Choose hold mode for a brief check: press, listen briefly, and release. In toggle mode, a second activation stops playback. Keep the device away from ears and stop if the sound feels uncomfortable. Leave the tab visible throughout this check. Switching away stops the app, so silence after returning does not by itself mean Firefox has failed.

Check that system sound is not muted, while keeping its volume low.
Read the app gain value; a zero setting produces no output.
Use the pointer first so keyboard focus does not confuse the result.

Move down from a silent high preset

Select steady mode and set 440 Hz for a short comparison. The frequency controls include coarse changes of 100 Hz. Read the displayed setting after each adjustment. The five presets request 4, 8, 12, 16, and 18 kHz, but each is limited by the current audio cap. That cap is the rounded-down value of the actual AudioContext sample rate multiplied by 0.45. It describes digital tone generation. It does not certify what a phone or laptop speaker can play. Many such speakers cannot reproduce ultrasonic frequencies. If a lower setting sounds while a higher one does not, leave the gain alone and record that simple observation.

Change frequency without changing gain during this comparison.
Do not use silence at a high setting as a hearing test.
A visible frequency value is not a measurement of speaker output.

Compare one marker, then check the controls

Stop the whistle before trying a classic or soft clicker marker. Quick yap is another synthetic marker option. A marker comparison can show whether a different app sound reaches the selected output, but it cannot verify the whistle frequency. Return to steady mode afterward. Pulse and warble change how the whistle sounds over time, which can make a first check harder to interpret. The whistle uses a 10 ms cosine fade at its edges. That brief fade is separate from the longer silent intervals you may notice in pulse mode.

Space toggles playback when you are not typing.
Escape stops sound unless focus is in a typing field.
Use the visible stop control whenever keyboard behavior is unclear.

Repeat only after checking what changed

If sound stopped after another app interrupted playback, return to Firefox and start a fresh brief check. Stop manually before connecting or removing an audio device. The app stops when it receives a devicechange event, but browser support is incomplete. Do not count on every output switch being reported. After changing the output, check system volume again before pressing play. If the page was opened offline, its installed version needs a prior successful cache. Offline operation is not promised for every browser situation. Reopen the site online if its controls did not load properly.

Keep frequency, mode, and gain unchanged when comparing two outputs.
End the check if either you or the dog appears uncomfortable.
Dogs differ; a reaction does not confirm a particular sound level.

Open the Firefox tab, lower system volume, and check that app gain is above zero.
Select steady mode at 440 Hz and make one brief direct press.
If needed, stop and compare a single clicker marker at the same system volume.
After any interruption or output change, review the controls before restarting.

Should I raise gain until the 18 kHz preset becomes audible?

No. Speaker limits can explain silence. Use a lower frequency for the playback check instead of increasing loudness.

Why did playback end when I opened another tab?

Keep Firefox on the visible whistle tab and press the playback control directly.. Return to the page and press playback again when ready.

Does Firefox need microphone access for this whistle?

The app does not use a microphone. Its tone is generated locally, so a microphone permission is not part of this check.

Online Dog Whistle and Whistle Tone Generator