Independent study

AI interpreting adds accuracy.

In an independent validation study led by Michal Schuster, PhD, No Barrier’s AI interpreter scored 6.38 out of 7 for accuracy, where 7 means no errors. It stayed highly accurate both from English to Spanish (6.26) and from Spanish to English (6.51).

Analysis conducted in 2024 · Reviewed July 2026
Mean accuracy
Scale 1 to 7
No Barrier
6.38
Vendor 1
5.59
Vendor 2
4.93
Means of two evaluators' ratings per utterance.
The standard

Why human interpreting is the benchmark

01

What interpreters bring

Judgment, cultural mediation and presence.

02

What the system asks of them

In-patient or remote calls and a heavy cognitive load.

03

The question that matters

Accurate interpreting whenever care happens.

Study design

How the accuracy study was designed

Step 1

Corpus

5 vignettes, 91 utterances.

Step 2

Interpreting by phone

3 sources: No Barrier, Vendor 1 and Vendor 2.

Step 3

Expert evaluation

2 qualified medical interpreters rated 273 renditions on a 1 to 7 scale across 4 error types.

Step 4

Statistics

ICC 0.62. Friedman's ANOVA.

Results

How accurate is AI medical interpreting?

No Barrier’s AI interpreter scored 6.38 out of 7 for accuracy, where 7 means no errors.

Accuracy
Error types
By direction
Replay
No Barrier
Vendor 1
Vendor 2
No Barrier
6.38
Vendor 1
5.59
Vendor 2
4.93
1
2
3
4
5
6
7
Hybrid medical interpreting: AI and human

How AI and human interpreting work together

Measure
No Barrier
Vendor 1
Vendor 2
Mean accuracy (1 to 7)
6.38
5.59
4.93
Total errors
64
135
187
English to Spanish
6.26
4.99
3.93
Spanish to English
6.51
6.20
5.96
Lowest rendition score
2.5
1
1

AI-first interpreting

  • Consistency in both directions
  • Fewer omissions
  • Precise terminology
  • Instant access

Human interpreters

  • Nonverbal cues
  • Cultural mediation
  • Presence in emotional conversations
  • Judgment in complex exchanges
Error severity

Which medical interpreting errors matter most?

01

Wrong medical term

No Barrier
5
Vendor 1
18
Vendor 2
23
02

Omission

No Barrier
17
Vendor 1
53
Vendor 2
70
03

Substitution

No Barrier
28
Vendor 1
32
Vendor 2
39
04

Addition

No Barrier
14
Vendor 1
32
Vendor 2
55
2.5
/ 7

No Barrier's lowest score was 2.5/7. Both vendors had renditions rated 1 (completely incorrect).

The study did not grade severity. This ordering is editorial.
English and Spanish medical interpreting

How accurate is AI interpreting in English and Spanish?

English to Spanish
Spanish to English
No Barrier
6.26
6.51
Vendor 1
4.99
6.20
Vendor 2
3.93
5.96
Mean accuracy, scale 1 to 7

Most patients with limited English proficiency speak Spanish. When their provider speaks, they hear it in Spanish. That is exactly where No Barrier's accuracy stayed high.

Conclusion

Key findings: AI medical interpreting accuracy

01

Significantly more accurate

6.38
vs 5.59 and 4.93
02

Fewer errors of every type

64
vs 135 and 187
03

Steady in both directions

6.26 / 6.51
EN to ES / ES to EN
Limitations
  • Scripted conversations, clean audio
  • English and Spanish, other languages not yet tested
  • Two raters

From the front desk to discharge, AI interpreting you can rely on.

The No Barrier AI interpreting platform is already deployed across 300+ medical sites.

Schuster, M. "Comparing medical interpreting performed by human and machine interpreters."
All scores are means of two evaluators' ratings per utterance. Vendor names withheld.