Fix Telephone & Narrowband Audio
Phone calls and VoIP are limited to a narrow 300–3400 Hz band, which makes voices sound tinny and boxed-in. This tool extends the bandwidth to restore natural fullness.
AI model This tool runs a generative AI model on a GPU, so it takes longer than the instant filters. Free to try; paid plans get priority on the GPU.
How it works
Narrowband speech is missing both the low warmth and the high air of full-range audio. The model regenerates those missing bands, widening the voice from telephone quality toward studio quality.
What it's good for
- Recorded phone interviews
- VoIP and conference audio
- Voicemail and call-centre files
- Legacy narrowband recordings
Details
- Engine
- VoiceFixer
- Formats
- MP3, WAV, M4A, FLAC, OGG, AAC
- Price
- Free to try
Frequently asked questions
It substantially improves fullness and warmth, getting much closer to broadcast quality. The original band limit means it won't be identical to a studio mic, but the gain is large.
Super-resolution is general-purpose; bandwidth extension is tuned for the specific 300–3400 Hz telephone band and the artifacts that come with it.
It focuses on the band limit; if the call is also noisy, run background-noise removal first for the cleanest result.
It regenerates the missing low warmth and high air around the existing 300-3400 Hz band, so the person still sounds like themselves, just fuller - it isn't swapping in a different voice.
On clean calls the widened result is natural; on harsh, distorted or codec-mangled phone audio the regenerated bands can sound slightly synthetic, since they are inferred rather than recorded.
No - the output is a new wideband reconstruction, so save the raw call recording separately if you need the untouched original for evidence or archival.
It widens the band and adds fullness, but heavy codec warble is a different problem; pairing it with background-noise removal first gives the cleanest extension.