Voicemail to Text: What the Greeting and the Beep Do
The beep never shows up. We spliced a 1 kHz tone into a 14.5-second voicemail at four lengths, from 0.2 to 2 seconds. Five files including a 2 kHz run all returned the identical 217 characters and 43 words. The greeting is different: a recorded message before the beep is speech, so it comes back as text you did not ask for. Ours added 86 characters and 15 words to the front of the transcript. If you only want the caller's words, you cut the greeting, not the beep.
One voicemail, eleven files
The source is a 14.52-second message left in a normal speaking voice, 44.1 kHz mono, 1,280,742 bytes. It reads as 217 characters and 43 words, and it is the same text in every file below unless the greeting is in front of it.
- Bare message: 14.52 s, 1,280,742 bytes, 217 characters, 43 words.
- Greeting plus beep plus message: 22.99 s, 2,027,620 bytes, 303 characters, 58 words.
- Beep spliced into the middle at 0.2, 0.5, 1.0 and 2.0 seconds, plus one 2 kHz run: five files, all 217 characters.
- Beep placed before the message at 3, 5 and 8 seconds: three files, all 217 characters.
- Narrowband runs: 300 to 3,400 Hz band-pass at 16 kHz and 8 kHz, then MP3 at 16, 32 and 64 kbps.
The beep is invisible, at any length
This is the cleanest result in the whole test. A pure tone carries no phonemes, so there is nothing for the model to write. Four durations from a fifth of a second to two full seconds, all inserted at the same point. Every one returned 217 characters and 43 words. The 2 kHz version behaved identically.
The file sizes moved, because the files got longer: 1,298,382 bytes at the 0.2-second beep up to 1,457,142 at two seconds. The text did not move a character in any of them.
That answers a question people ask constantly, which is whether they need to strip the beep before uploading. You do not. It costs you nothing but file size, and even two seconds of it is 176 KB of dead weight in an uncompressed file.
The greeting does come back, and it is long
A recorded greeting is speech, so it transcribes like speech. Our test greeting - “You have reached the voicemail box of 5550123. Please leave a message after the tone.” - came back perfect on its own: 85 characters, 15 words, including the seven digits as one string.
Put it in front of the message and the two become one block. 303 characters, 58 words, in a single paragraph with no separator between the greeting and the caller. If you paste that into a note, the first sentence reads like the person you were trying to reach left you a message about a voicemail box.
- Greeting alone: 85 characters, 15 words, digits read as 5550123.
- Message alone: 217 characters, 43 words.
- Greeting plus beep plus message: 303 characters, 58 words.
- 85 plus 217 is 302, so the join added one character and no words lost.
That last line is the useful part. The greeting and the message add up almost exactly, which means the model handled the boundary correctly and did not drop the caller's first word. You are not losing anything by leaving the greeting in. You are just getting text you have to delete.
Cutting the front is easier than cutting the beep
We also tested a long tone in front of the message - three, five and eight seconds - with no greeting. All three returned 217 characters and 43 words. So a long lead-in is harmless too.
That gives you a simple rule. The audio a voicemail system adds is almost never the problem. Whether it is a 0.2-second tone or an eight-second one, it produces nothing in the text. The greeting produces text, and the text is at the front where you can trim it in one action.
Phone bandwidth costs you time, not words
Voicemail is stored narrowband on a lot of systems, so we built the phone version: everything above 3.4 kHz and below 300 Hz removed, resampled to 8 kHz. That file is 232,398 bytes against 1,280,742 - 5.5 times smaller - and it returned the same 217 characters and 43 words.
The cost showed up in the clock, not the text. The wideband file came back in 2.73 seconds. The 8 kHz version took 8.92 seconds. A 16 kHz version, at 464,718 bytes, took 4.09 seconds. Same text, three times the wait on the narrowest one.
- Wideband 44.1 kHz: 1,280,742 bytes, 2.73 s, 217 characters.
- Band-pass only, no resample: 1,280,742 bytes, 5.16 s, 217 characters.
- 16 kHz: 464,718 bytes, 4.09 s, 217 characters.
- 8 kHz: 232,398 bytes, 8.92 s, 217 characters.
The band-pass-only file is the interesting one. It has the same byte count as the original, because the filter changed the content and not the container, and it took nearly twice as long to process. Removing the top two thirds of the spectrum made the job harder, not easier, even though the words came back identical.
The smallest file was the slowest
One result is worth flagging without a tidy explanation. We encoded the 8 kHz version to MP3 at 16, 32 and 64 kbps. All three returned the same 217 characters and 43 words. The 16 kbps file is 29,636 bytes - 43 times smaller than the original - and it took 19.33 seconds, the slowest upload in the entire test.
- 16 kbps MP3: 29,636 bytes, 19.33 s, 217 characters, 43 words.
- 32 kbps MP3: 59,084 bytes, 2.12 s, 217 characters, 43 words.
- 64 kbps MP3: 118,124 bytes, 2.50 s, 217 characters, 43 words.
The 32 kbps file is the smallest one that also came back fast, and it is 43 percent smaller than the 64 kbps version with identical text. If you are squeezing a voicemail to get it under a size limit, that is the rung to pick. Going lower bought nothing but nine extra seconds of waiting.
What this means for a message you are about to send
If you are recording the greeting, the length of it does not matter to the transcript, but the words do, because they will be the first thing in it. Keep the greeting short and put the caller's name late, so trimming the front is obvious.
- Do not bother removing the beep. It never produces text.
- Do trim the greeting, or expect 85 extra characters at the top.
- If the caller starts mid-word because the beep cut them off, that word will be mangled - the tone itself is silent to the model, but it still covers audio.
- Narrowband is fine. It costs seconds, not words.
- Resample to 16 kHz before encoding to MP3 if you need a small file. That combination stayed under three seconds.
Got a Reel you want as text? Download the Instagram transcript as TXT, SRT, or VTT →
The greeting is the part that ends up in your text, and it is the part a tone never touches. Wondershare UniConverter trims the front of a voicemail on your own machine and writes a clean file that starts on the caller's first word, so you are not deleting 85 characters of somebody else's recorded message by hand every time. It does not transcribe - the words come back from this page.
FAQ
Does the beep in a voicemail show up in the transcript?
No. We spliced a 1 kHz tone into a message at four durations from 0.2 to 2 seconds. Every file returned the identical 217 characters and 43 words. A pure tone has no phonemes to write.
Why does my voicemail transcript start with the greeting?
Because a recorded greeting is speech and transcribes like speech. Our test greeting added 85 characters and 15 words to the front of a 217-character message. The two portions added up almost exactly, so nothing was lost - you just have text to delete.
Should I convert voicemail to a lower sample rate before uploading?
It changes nothing in the text. Our 8 kHz version was 5.5 times smaller and returned the same 217 characters and 43 words, but it took 8.92 seconds against 2.73 for the wideband file. Narrowband costs you time, not accuracy.
What bitrate should I use for a voicemail MP3?
32 kbps. All three MP3 rungs returned the same text, but the 16 kbps file took 19.33 seconds while 32 kbps took 2.12. The 32 kbps file was also 43 percent smaller than 64 kbps with no difference in the words.