What actually causes bad call transcription, and which causes can I fix?
Most transcription damage comes from the recording path rather than the speaker. Aggressive audio compression, mono mixing, low sample rates and hold-music bleed are configuration choices you control. Wind, road noise, speakerphone echo and crosstalk come from the caller and you cannot. Accents and trade jargon matter less than people expect, and both improve when the system is given your vocabulary of brands, services and place names.
Fixable at the phone system
These are settings, not limitations, and they are worth auditing before anyone concludes the transcription is weak.
- Recording codec and bit rate. Heavily compressed recordings sound acceptable to a human ear and lose exactly the high-frequency detail that distinguishes consonants.
- Mono versus dual channel. Mixing both parties into one track costs speaker accuracy and makes crosstalk unrecoverable.
- Recording start point. If recording begins after the greeting, you lose the disclosure and the opening, which are often the parts being evaluated.
- Hold music captured on the customer channel. Music over speech is one of the hardest conditions for any recognizer.
Not fixable, but manageable
Callers phone from trucks at highway speed, from windy job sites, from a speakerphone across a kitchen. That audio is what it is. What you can do is detect it and flag it, so a call with a low audio-quality score is not fed into a coaching metric as though it were clean.
Marking audio quality per call, and excluding the worst tier from behavioral scoring, prevents the most common credibility failure: a rep being shown a poor score that came from a call nobody could hear. Treating quality as metadata rather than an afterthought is part of how we set up call analysis.
Accents, dialects and code-switching
Modern recognizers handle a wide range of accents better than their reputation suggests, and the practical failures are more often vocabulary than pronunciation. A caller switching between languages mid-sentence is genuinely difficult, and results vary by language pair and by how much of each language appears.
Where a bilingual customer base is a routine part of the business, this deserves explicit planning rather than an assumption that it will work. Bluefrog's voice translation technology is in development, and we describe it that way deliberately rather than implying a capability that is not yet shipped.
Give the system your vocabulary
Every trade has words that are rare in general speech: equipment brands, product lines, local street and subdivision names, the way your company refers to its own service tiers. Supplying that list measurably improves the strings that matter most, because those are precisely the words a general model has the least evidence for.
This is a small piece of configuration with an outsized effect, and it is the kind of thing that separates a working deployment from a demo. It belongs in the same category as mapping your service categories and your ad sources during systems integration.
Topics: audio quality · transcription · recording configuration · noise
Have a version of this question about your own business?
The useful answer usually depends on which systems you run and how they're connected. That's a conversation, not a blog post.