How many hours of audio does a typical qualitative study produce?
Most qualitative interview and focus-group studies produce between 4 and 17 hours of audio. Interview studies land near 9 to 17 hours, because 9-17 interviews reach data saturation (Hennink & Kaiser, 2022) at about an hour each. Focus-group studies run lower, near 4 to 12 hours.
Here is the audio math by format, using saturation-based study sizes: - Interview study: 9-17 interviews to saturation at about 1 hour each, so roughly 9-17 hours of audio - Focus-group study: 4-8 groups at 60-90 minutes each, so roughly 4-12 hours - Single interview: 30 minutes to several hours, conducted once per participant - Ethnography: no peer-reviewed typical figure; recorded hours vary widely with fieldwork length and scope
One reframe prevents planning errors. Audio hours track the number of recorded sessions and their length, not the headcount. A single focus group with 8 participants still yields one recording, so eight voices never mean eight hours.
How many interviews does a study need before it's enough?
Saturation usually arrives fast. An experiment on 60 in-depth interviews found saturation within the first 12 interviews, with metathemes visible by interview 6 (Guest, Bunce & Johnson, 2006). A 2022 systematic review set the typical band at 9-17 interviews (Hennink & Kaiser, 2022).
Two independent datasets tell the same story. In the authors' 2023 seminar figures, about 91% of interview codes were developed by interview 9, though a few themes reached full meaning saturation only near interviews 16 to 24 (Hennink & Kaiser, 2023). Plan toward the top of the range when your sample is diverse.
That count is your first audio input. A homogeneous study with tight objectives often needs 9 to 12 interviews; a broader design pushes toward 17 or more. Our guide to qualitative research transcription covers turning that recording pile into analyzable text.
Interview length: 30 minutes to several hours
A single in-depth interview runs from 30 minutes to several hours, and teams usually conduct it only once per participant (DiCicco-Bloom & Crabtree, 2006). That is the defensible peer-reviewed range. For planning, many teams use about 60 minutes as a working midpoint, not a fixed rule; length varies by interview type, from ~20-minute surveys to multi-hour in-depth sessions.
Multiply count by length and the audio total appears. At a 60-minute working average, 9 interviews make about 9 hours and 17 make about 17. Stretch interviews to 90 minutes and the same study climbs to roughly 14 to 26 hours.
Longer interviews cost more than storage. Every recorded hour becomes text you clean, timestamp, and code. See how to transcribe an interview for the workflow that turns one recorded hour into a usable transcript.
How much audio does a focus-group study produce?
Focus-group studies produce less audio than their participant counts suggest. Saturation typically arrives within 4-8 group discussions (Hennink & Kaiser, 2022), and each group runs 60-90 minutes (Hennink, Kaiser & Weber, 2019). That works out to about 4 to 12 hours of recording.
Themes surface even faster than the group count implies. Across 40 focus groups, more than 80% of themes appeared within 2-3 groups and 90% within 3-6, and 3 groups captured every most-prevalent theme (Guest, Namey & McKenna, 2017).
Headcount does not add hours here. A group holds 5-10 people, 6-8 preferred (Krueger, 2002), yet still yields one recording. In one empirical test, 4 groups reached code saturation at 94% of codes (Hennink, Kaiser & Weber, 2019), so 4 to 6 hours often covers a focused question.
Worked examples: three study designs, three audio totals
Put the numbers together and three designs bracket most projects. Using saturation-based sizes, a lean interview study lands near 9 hours, a full one near 17, and a focus-group study near 4 to 12 hours (Hennink & Kaiser, 2022). Here is the arithmetic.
Three worked totals, at a 60-minute interview average and 60-90 minute groups: - Lean interview study: 9 interviews x 60 min = about 9 hours of audio - Full interview study: 17 interviews x 60 min = about 17 hours; at 90 min, about 26 hours - Focus-group study: 4-8 groups x 60-90 min = about 4 to 12 hours - Ethnography: highly study-specific, with no peer-reviewed typical audio figure; recorded hours depend on fieldwork length and scope
Treat these as planning brackets, not guarantees. Diverse populations, multiple sites, or repeat interviews push totals higher. The analysis stage then works from that full audio pile, so an accurate hour count early keeps coding timelines honest.
What do audio hours mean for your transcription plan?
Audio hours set your transcription clock. A 12-interview study at an hour each is 12 hours of recording, and every hour must become text before analysis starts (Guest, Bunce & Johnson, 2006). Knowing the total up front is how you budget time and cost.
Manual transcription is the slow part. Each recorded hour takes far longer to type up than to record, which is why teams estimate the full pile early. See how long it takes to transcribe a whole study, the per-hour breakdown, and our overview of transcription in academic research for the time and accuracy tradeoffs.
This is where automated transcription helps. Once you know a study yields about 12 hours of audio, a tool like Pepys converts the recordings to text in a predictable window. The hour count still comes from study design, not the software.