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canonical: https://biosonic.io/compare/bto-acoustic-pipeline
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# BioSonic vs BTO Acoustic Pipeline

Last updated: 2026-04-26

BioSonic and the BTO Acoustic Pipeline both classify bat calls from WAV recordings, but they take different roads to get there. BioSonic is a browser-based platform that uses deep learning image recognition on spectrograms. The BTO Acoustic Pipeline is a service run by the British Trust for Ornithology, using machine learning classifiers built by Dr Stuart Newson and Dr Simon Gillings. Both are serious tools. This page lays out where they overlap and where they diverge, so you can pick the right one for your project.

## At a glance

| Feature | BioSonic | BTO Acoustic Pipeline |
|---|---|---|
| Underlying approach | Deep learning image recognition on spectrograms | Random Forest classifier (TADARIDA, Bas et al. 2017) for bats; CNN for birds (Gillings & Scott 2021) |
| Training data | 2.5M bat calls + 4M noise files, curated by 12 bat experts | ~170K bat call recordings |
| Benchmarked accuracy | 98.7% F1 (third-party benchmark by Wilder Sensing, 6,126 calls, 15 species) | Not publicly benchmarked at scale |
| Platform | Browser-based — works on any computer | Desktop uploader app + cloud processing |
| Team workflow | Unlimited users per organisation; shared projects; in-app review | No in-platform team review UI; users manage locally after results return |
| Taxa | Mainly bats. Birds and small mammals coming soon | Bats, small mammals, bush-crickets, birds (separate classifiers) |
| Social and feeding calls | Separated automatically | Separated (echolocation, social, feeding buzz) |
| Noise filtering | Deep-learning noise model trained on 4M non-bat recordings | Filtering as part of classifier |
| Model updates | New AI model every weekend | Very few updates |
| Storage | 9 years EU-hosted included | Recordings not stored long-term unless bespoke project |
| Report generation | One-click charts, maps, Word export | Results returned as files; reporting is user's responsibility |
| Detector compatibility | Any WAV-producing detector | Any WAV-producing detector |
| Geographic coverage | UK, Netherlands, Denmark, Germany, Sweden | UK + Europe-wide (25+ countries) |
| Pricing model | Per-GB-per-year, all-inclusive; contact for quote | Free tier requires data sharing (100 credits/year, approx. 100 GB); without sharing £1.40/GB; PAYG bundles; Bespoke projects from £573 |
| Free trial | Yes | Free tier available |

## How each tool identifies bats

BioSonic converts each audio recording into a spectrogram image and runs it through a convolutional neural network trained on 2.5 million labelled bat calls and 3.5 million noise files. The model learns to recognise species from the shape, frequency, and timing of calls in the image, rather than from a handcrafted set of acoustic parameters. This approach means the system can pick up subtle patterns that are hard to encode manually, and the model is retrained every weekend as new verified data comes in.

The BTO Acoustic Pipeline takes a different approach. Its bat classifier uses Random Forest (TADARIDA, Bas et al. 2017), while bird identification uses CNN classifiers (Gillings & Scott 2021). The pipeline handles not just bats but also small mammals, bush-crickets, and birds using separate classifiers. For UK bat species in particular, the BTO team has deep domain expertise and their classifiers reflect that.

The fundamental difference: BioSonic is a self-service platform where you upload, review, and report within a single browser interface. The BTO Acoustic Pipeline is a processing service — you submit recordings via a desktop uploader, results come back as files, and downstream analysis is your responsibility.

## Accuracy comparison

In the same [Wilder Sensing benchmark](/benchmarks), BioSonic was tested on 6,126 bat calls and scored 98.7% F1. BTO Acoustic Pipeline couldn't be benchmarked the same way — the report concluded: "BTO Pipeline is the least suitable bat analysis software… due to the inability to manually validate the AutoID results using the BTO Pipeline platform."

| Metric | BioSonic | BTO Acoustic Pipeline |
|---|---|---|
| F1 score | 98.7% | Not benchmarkable* |
| Manual validation | Right-click on spectrogram | Not supported on platform |
| False detections of impossible species | None | Greater horseshoe (validated as Noise) & Escalera's bat (rare vagrant) — neither present in survey region |
| File handling | Any length, any folder size | Auto-splits into 5-sec segments → inflated counts & more NoIDs |
| RAG score (Wilder Sensing) | 16 / 18 | 9 / 18 — lowest of all 3 tools tested |

*BTO could not be benchmarked because the platform does not support manual validation of AutoID results, and the CSV output is only compatible with Analook Insight, an outdated analysis tool.

Have labelled recordings? [We will run a free comparison](mailto:josef.carlson@biosonic.se).

## What Wilder Sensing found when testing BTO

> "BTO Pipeline is the least suitable bat analysis software for Wilder Sensing."
> — Wilder Sensing benchmark report, 2025

> "BTO falsely detected Greater horseshoes with high confidence levels — but they were validated as Noise files."
> — On BTO's false positives in Norfolk

> "Cannot manually validate results. The csv. output file is only compatible with Analook Insight, an outdated bat analysis software."
> — On the validation gap

> "BTO automatically splits wav. files longer than 5 seconds into 5-second segments, resulting in more low confidence levels and NoIDs."
> — On BTO's file-splitting (inflated 1,227 detections vs BioSonic's 745 on the same data)

## Day-to-day workflow

### Uploading recordings

With BioSonic, you open a browser, drag files into a project, and the AI begins processing immediately. There is nothing to install. With the BTO Acoustic Pipeline, you download and install a desktop uploader application, configure your submission, and upload files for cloud processing. Results are returned as downloadable files.

### Reviewing results

BioSonic provides an in-app review interface where ecologists can inspect spectrograms, confirm or override AI classifications, and flag uncertain calls for a second opinion. Every decision is logged with a timestamp and user ID. The BTO Acoustic Pipeline returns classification results as data files. Review and quality assurance happen in whatever tools your team already uses — typically spreadsheets or GIS software.

### Generating reports

BioSonic includes one-click report generation: activity charts, species heatmaps, GPS-linked maps, and Word export formatted for planning applications. The BTO Acoustic Pipeline does not include a reporting layer. Building client-ready deliverables from the output files is up to you.

### Noise handling

Rain, wind, insects, and equipment noise are the bane of bat acoustic surveys. BioSonic applies a dedicated deep-learning noise model trained on 3.5 million non-bat recordings to filter noise before classification. The BTO Acoustic Pipeline handles noise as part of its classification pipeline, filtering out non-target sounds during the identification process.

## Working as a team

Bat survey work is rarely a solo effort. A typical consultancy has field technicians deploying detectors, junior ecologists doing first-pass review, and a named ecologist signing off reports. BioSonic is built for this: unlimited users per organisation, shared project dashboards, in-app review queues, and a full audit trail. Everyone works in the same browser interface, on the same data, in real time.

The BTO Acoustic Pipeline does not include team collaboration features. Each user submits and receives results individually. Coordinating across a team means sharing files externally and managing review in spreadsheets or email. For solo researchers or small citizen-science projects, this is often fine. For a 15-person consultancy running 40 concurrent surveys, it becomes a bottleneck.

> "Since joining BioSonic our analysis time has reduced significantly. The team is excellent in their support, super quick to respond."
> — Luke Waddison, Ecological Consultant, [Wharton](/wharton) (UK)

## What UK consultants say

We asked bat ecologists who have used both tools to describe their experience. These are direct quotes from working consultants, not marketing copy.

| Category | BioSonic | BTO Acoustic Pipeline |
|---|---|---|
| Overall | "Super impressed. Super intuitive to use. Nothing annoyed me." | Cheap, but prep + upload friction is high. |
| 5-sec file limit | Accepts any file length — "just drag a folder in and forget about it, let it turn away in the background." | Requires strict 5-second files. Takes days of mind-numbing work to sort. |
| Folder size limit | Accepts any folder size. | "Only takes 29 GB folders, so you have to split everything manually." |
| Upload experience | "Just drag a folder in and kind of forget about it." | "Nightmarish. You've got to break it into ~30 GB folders and queue them — total nightmare." |
| Spectrogram review | "Being able to fly through yours would save a lot of time." "Drawing the box with right-click — that was nice." | No spectrogram review built in. |
| UI / UX | "Not glitching or crashing. Super easy to use." | — |
| Emergence graphs | "Yeah, that's really cool. This would be really good to have." | "I tried doing that years ago. It took me about two weeks on Excel. It was so painful." |
| Graphs & charts | "These graphs would be so useful and save us a lot of time. That'd be really useful for swarming stuff." | Manual pivot tables — "probably human error by the 200th pivot table." |
| Collaboration | "If I could share my project with Josh, just send a link — that'd be great." | — |
| Data storage | "That's a massive selling point" (long-term storage + re-download). | Separate costly Azure storage. |
| Summary | Built for real UK bat consultant workflows: minimal prep, fast proofing, one-click graphs, collaboration, storage, and huge time savings. | Strict limits, heavy manual prep, time-consuming script workarounds, and high friction despite being cheaper per GB. No review built in. |

## Time savings at scale: 7.5 TB season estimate

To make the workflow difference concrete, we estimated the hours a UK consultancy would spend processing 7.5 TB of bat recordings in a single season using each tool. BioSonic saves an estimated 193 hours — roughly 5 full-time weeks.

| Work item | BioSonic (hours) | BTO (hours) | Extra BTO hours |
|---|---|---|---|
| Sound analysis review | 80 | 141 | 61 |
| Upload admin (30 GB folder cap) | 0 | 23 | 22.8 |
| One-click charts & maps | 4 | 28 | 23.6 |
| Emergence graphs | 1 | 12 | 10.8 |
| Custom charts & maps | 7 | 28 | 20.6 |
| Weather data integration | 0 | 14 | 14 |
| 5-sec file conversion | 0 | 15 | 15 |
| Rework / duplicated review | 5 | 16 | 10.6 |
| Direct support (WhatsApp group) | 0 | 14 | 14.4 |
| **Total hours** | **97** | **290** | **193** |
| **Full-time weeks** | **2** | **7** | **5** |

That is a 67% reduction in analyst time. At £65 per hour, the 193 extra hours with BTO represent roughly £12,500 of additional labour cost per season — before accounting for the stress of manual file splitting, pivot-table errors, and the absence of built-in review tools.

## Pricing model

BioSonic charges per GB per year on an all-inclusive basis. That price covers AI classification, 9 years of EU-hosted storage, unlimited users, report generation, and ongoing model updates. There are no per-seat fees and no feature tiers. [Contact us for a quote](https://cal.com/biosonic/30min).

The BTO Acoustic Pipeline offers several pricing options:

- **Free tier:** 100 credits per year (approximately 100 GB), but this requires sharing your recordings with BTO for use in classifier training.
- **Standard (no data sharing):** £1.40 per GB.
- **PAYG bundles:** volume discounts available.
- **Bespoke projects:** from £573 for custom analysis work.

The free tier deserves a closer look. It requires sharing your recordings with BTO for classifier training. For citizen science and some NGO-funded work, this is a reasonable trade. For commercial consultancies working under NDA with wind farm operators or property developers, sharing client site recordings with a third party is often a dealbreaker. If your contracts include data confidentiality clauses, check whether the free tier's data-sharing requirement is compatible before committing.

## Who should choose which

### Choose BioSonic if:

- You run a consultancy or survey team that needs shared projects, in-app review, and one-click reporting.
- You work across multiple European countries and need consistent performance outside the UK.
- Data confidentiality matters — your clients require that recordings stay within a controlled platform.
- You want long-term storage included without managing your own archive.
- You value weekly model updates over periodic releases.

### Choose BTO Acoustic Pipeline if:

- Your work is exclusively UK-based and you want classifiers built by UK bat specialists with decades of local data.
- You need non-bat taxa — birds, small mammals, bush-crickets.
- You are running a citizen-science project and the free tier's data-sharing requirement is acceptable.
- You are a solo researcher who prefers working with raw data files and building your own analysis pipeline.
- Geographic coverage across 25+ countries matters more than team workflow features.

These are not mutually exclusive. Some consultancies use BTO for UK-only surveys where the free tier works, and BioSonic for commercial projects where data confidentiality and team workflow are priorities. The tools accept the same WAV files, so running both in parallel is straightforward.

## Switching from BTO Acoustic Pipeline to BioSonic

There is no format lock-in with either platform. Both accept standard WAV files from any bat detector. If you are currently using the BTO Acoustic Pipeline and want to try BioSonic, the process is simple:

- **Step 1:** [Create a free BioSonic account](https://bat.biosonic.se/signup).
- **Step 2:** Upload the same WAV files you would normally send to BTO.
- **Step 3:** Compare results side by side on your own data.

Most users see results within hours of uploading. If you want a guided migration or have questions about how BioSonic handles specific species groups, [email us directly](mailto:josef.carlson@biosonic.se) or [book a 30-minute call](https://cal.com/biosonic/30min).

Your existing BTO results are yours to keep. BioSonic does not require you to abandon any previous analysis — you are adding a tool, not replacing an entire workflow overnight.

## Frequently asked questions

### Is the BTO Acoustic Pipeline free?

BTO offers a free tier of 100 credits per year (roughly 100 GB), but it requires you to share your recordings with BTO for classifier training. If you cannot share data — for example, because of client NDAs — standard pricing is £1.40 per GB with no data-sharing requirement. PAYG bundles and bespoke project pricing are also available.

### Can I use BioSonic for UK bat species?

Yes. BioSonic supports all UK bat species and is used by UK-based consultancies for commercial survey work. The AI model is trained on 2.5 million bat calls spanning European species, including all 18 UK breeding species. See our [benchmarks page](/benchmarks) for accuracy data.

### Does the BTO Acoustic Pipeline store my recordings?

Not by default. Recordings are processed and results returned, but long-term storage is not included unless arranged as part of a bespoke project. BioSonic includes 9 years of EU-hosted storage as standard with every account.

### How does accuracy compare between BioSonic and BTO?

In a third-party benchmark by Wilder Sensing, BioSonic scored 98.7% F1 on 6,126 calls across 15 species. BTO Acoustic Pipeline could not be benchmarked the same way — the report found that BTO's platform does not support manual validation of AutoID results, and concluded it was "the least suitable" of the three tools tested. BTO also falsely detected impossible species (Greater horseshoe bats validated as Noise) and inflated detection counts by auto-splitting files into 5-second segments. [See full benchmark results](/benchmarks).

### Can my whole team use BioSonic on one account?

Yes. BioSonic supports unlimited users per organisation with shared projects, in-app review queues, and a full audit trail. There are no per-seat fees. Every team member works in the same browser interface. BTO Acoustic Pipeline does not include in-platform team features — collaboration happens outside the tool.

### What bat detectors work with each platform?

Both BioSonic and BTO Acoustic Pipeline accept WAV files from any bat detector. Audiomoth, Wildlife Acoustics, Pettersson, Batlogger, Elekon — if it produces WAV output, it works with both platforms.

### Can I switch from BTO Acoustic Pipeline to BioSonic mid-season?

Yes. There is no format lock-in. Upload your WAV files to BioSonic and results are typically ready within hours. You can run both platforms in parallel on the same recordings if you want to compare before committing. [Start a free trial](https://bat.biosonic.se/signup) to test it with your own data.

## Sources

- Wilder Sensing (2025). Third-party benchmark report — BioSonic scored 98.7% F1; BTO rated least suitable of three tools tested. [See benchmarks page](/benchmarks)
- Bas, Y. et al. (2017). "Tadarida: A toolbox for animal detection on acoustic recordings." J. Open Res. Softw. 5(1):6
- Gillings, S. & Scott, C. (2021). CNN classifiers for bird sound identification — BTO Research Report
- BTO Acoustic Pipeline pricing: [bto.org](https://www.bto.org/our-science/projects/bto-acoustic-pipeline)

Last verified: 2026-04-26.

## Ready to try it?

Upload a batch of WAVs and compare results against your current workflow. No commitment, no credit card, no data sharing required.

[Start free trial](https://bat.biosonic.se/signup) | [Book a demo](https://cal.com/biosonic/30min)

Questions? Email [josef.carlson@biosonic.se](mailto:josef.carlson@biosonic.se)