Head to head · Voice agents · October 2026 research run

Amazon Nova 2 Sonic vs Hume EVI (Empathic Voice Interface)

Amazon Nova 2 Sonic scores 67.6 (B) on agent readiness against Hume EVI (Empathic Voice Interface)'s 54.1 (C), and leads in 4 of 7 scored categories. Hume EVI (Empathic Voice Interface) leads on schema & documentation and payments & pricing. Both do voice agents.

Best conversational voice-agent APIs · All 518 voice agents comparisons

Which one, for what

Amazon Nova 2 Sonic B

Best for Voice agents on AWS, call centres on Amazon Connect, teams that want IAM and in-account data handling.

Ahead on

  • Reliability, 95 against 55
  • Security & auth, 77 against 27
  • Maintenance & community, 50 against 35
  • Transparency & trust, 79 against 61

Watch for

Connections end after 8 minutes, so long calls need the session-continuation pattern

Hume EVI (Empathic Voice Interface) C

Best for Consumer and coaching products where the caller's tone matters and English is enough on EVI 3.

Ahead on

  • Schema & documentation, 90 against 75
  • Payments & pricing, 37 against 10

Also in its favour

  • A hosted endpoint, with nothing to install

Watch for

Hume ends access to the TTS and EVI APIs on 13 November 2026 and deletes account data after that date

Why the edge

Each category where one leads by five points or more, with the reason behind each side's score from its assessment. The numbers are in the table below; this is what they stand for.

Security & auth Amazon Nova 2 Sonic +50

Amazon Nova 2 Sonic 77

SigV4 with IAM roles and temporary credentials scoped per model ARN, as the Sonic quickstart signs (30). Tools run in the client, so side effects are the developer's to approve, and IAM can restrict which models a role invokes, with no approval step in the API (12 of 20). The model listens to callers and acts on tool results, and no prompt-injection guidance was found in the Sonic guide (5 of 15). CloudTrail logs Bedrock API calls, read as amazon-nova-embeddings was (12 of 15). VDP on HackerOne, Bedrock in SOC scope and a valid security.txt on aws.amazon.com, with no paid bounty, as on the other AWS listings (18 of 20). Total 77.

Hume EVI (Empathic Voice Interface) 27

One API key and secret key pair per account, replaced as a whole with 'Regenerate keys', plus 30-minute access tokens from a client-credentials endpoint (15). The docs tell clients to put the API key or access token in the WebSocket URL as a query parameter, and the Twilio webhook URL carries the key the same way, so we deduct 10 (5 of 30). No scoped or read-only keys (3 of 20). EVI listens to callers and we found no prompt-injection guidance (5 of 15). Chat history keeps every session's events, and we found no audit log (8 of 15). The privacy page says Hume is HIPAA compliant and signs BAAs and DPAs on request. No security.txt, SOC 2 report or bug bounty found (6 of 20). Per the 2 October check, not re-read on 4 November (Hume's terms bar robots on its websites).

Reliability Amazon Nova 2 Sonic +40

Amazon Nova 2 Sonic 95

Hosted reading. AWS Health Dashboard with per-service, per-Region history (20). The dashboard history file (newest event 30 October 2026) lists no Bedrock event in the 90 days from 8 August, and the 3 September us-west-2 event names STS, Connect and IAM Identity Center, not Bedrock. The public dashboard records broad events only, so 25 of 30, as amazon-nova-embeddings was read. Quotas published, 20 concurrent requests per Region, not adjustable (15). The stream API lists ThrottlingException (429), ServiceUnavailableException (503), ModelTimeoutException (408) and ModelStreamErrorException (424), Bedrock's troubleshooting guide advises backoff with jitter, and the 8-minute connection limit comes with a session-continuation sample (15). Bedrock's SLA of 99.9 per cent a month per Region for model APIs, as read for amazon-nova-embeddings on 1 November (10). Generally available since 2 December 2025 (10). 20 + 25 + 15 + 15 + 10 + 10 = 95.

Hume EVI (Empathic Voice Interface) 55

Hume's Terms of Service (last updated 5 October 2026) bar access to any portion of the Service, which includes its websites, through spiders, robots, crawlers or data mining tools, so no hume.ai page, status.hume.ai included, was re-read on 4 November. Readings are per the 1 and 2 October checks. A status page at status.hume.ai with component history back to September 2025 (20). Today's window runs from 6 August. Its readable part, 6 August to 2 October, holds one incident, TTS down for about 7 minutes on 19 September, which names TTS and not EVI. The EVI outages of 11 July (about 6.5 hours) and 24 July (about 2.6 hours) are now outside the window, and 3 October to 4 November is unread. A window that is partly unread holds at its recorded award and isn't credited for the unread stretch, as mailtrap's was after its majors aged out, so the line stays at 5 until the rest of the window can be read (5). Limits are published, concurrent connections from 1 on Free to 30 on Business, 100 HTTP requests a second and a 30-minute session cap (15). The error catalogue has a rate-limit code (E0811, 'Retry later') and a too-many-chats code (E0700) that states the active count and limit, but no HTTP 429, Retry-After or backoff guidance (5 of 15, held partial). No SLA found (0). EVI 3 is the generally available default per the 30 September check (10). 20 + 5 + 15 + 5 + 0 + 10 = 55.

Payments & pricing Hume EVI (Empathic Voice Interface) +27

Amazon Nova 2 Sonic 10

No x402, MPP or L402 (0). The Nova and Bedrock pricing pages carry a speech-to-speech table drawn by script, so the per-token prices weren't read and this line scores absent, which is our reader's limit and not the vendor's (0). New accounts get up to $200 in Free Tier credits, and the Free Tier FAQ says most new customers need no payment method, read as half on the other AWS listings (10). A person signs up for an AWS account in a browser (0). Total 10.

Hume EVI (Empathic Voice Interface) 37

No x402, MPP or L402 (0 of 40). Plan prices and per-minute overage from $0.06 to $0.04 are on the public pricing page (20). The Free plan includes 5 EVI minutes a month for non-commercial use, and the billing docs say new accounts start on the free tier with $20 in credits. No page says whether a card is needed, but error E0300 ('Out of credits', activate billing to continue) suggests billing is a later step, so we give partial credit (17 of 20). Access starts with a human signup (0). Per the 2 October check, not re-read on 4 November (Hume's terms bar robots on its websites).

Transparency & trust Amazon Nova 2 Sonic +18

Amazon Nova 2 Sonic 79

Closed model under the AWS Service Terms, with Apache-2.0 SDKs and samples (15). Bedrock stores no inputs or outputs by default and model providers can't see them, Sonic isn't on the abuse-detection page's list of models whose traffic is stored, and section 50.3 doesn't list Bedrock among services whose content improves AWS services, as read for amazon-nova-embeddings on 1 November (22 of 30). Bedrock's lifecycle policy for models launched before 7 September 2026 promises 12 months and a Legacy period of at least 6 months, but the March and May refreshes changed the model in place under the same ID (15 of 20). Regions are listed, with sub-processors not read (12 of 20). Total 64.

Hume EVI (Empathic Voice Interface) 61

Closed service with clear terms and MIT SDKs (18 of 30). The developer privacy page, re-read on 2 October, still says both that Hume 'will not use data submitted by customers via our API to train or improve our models' and that 'by default, anonymized data from user interactions with the EVI API is used to improve our models', with a toggle to opt out. Retention is on by default with a 'Do not retain data' toggle. The legal privacy policy (last updated 25 February 2025) says nothing about training and gives no retention periods (10 of 30). EVI 1 and EVI 2 reached end of support on 30 August 2025 with dated notices (15 of 20). Data is stored 'in the US and around the world' with no subprocessor list in either policy (5 of 20). Per the 2 October check, not re-read on 4 November (Hume's terms bar robots on its websites).

Schema & documentation Hume EVI (Empathic Voice Interface) +15

Amazon Nova 2 Sonic 75

The Bedrock service model types InvokeModelWithBidirectionalStream, but the Sonic events inside it (session, prompt, content, tool and usage events) are JSON payloads documented only in the guide, with no schema file (12 of 25). llms.txt and Markdown copies of the Nova 2 guide (10). Guides on the event lifecycle, barge-in, turn-taking, async tools and chat history say when and how to use each (16 of 20). Event fields are documented as JSON examples and tables, not typed schemas (10 of 15). Sample repositories in several languages and the API's exceptions with HTTP codes (12 of 15). Release notes and document history, with in-place model refreshes and a versioned model ID (15). Total 75.

Hume EVI (Empathic Voice Interface) 90

llms.txt links an AsyncAPI 2.6.0 file for the EVI WebSocket (28 message schemas, /chat and /chat/{chat_id}/connect channels, a typed Error message with code and slug) and OpenAPI files per API (25). llms.txt (10). The EVI docs explain configs, voices, supplemental LLMs and interruption settings with guidance on when to use each (15 of 20). Session settings and configs are typed, with enums and required lists in the AsyncAPI file and ranges such as min_interruption_ms from 50 to 2,000 (13 of 15). Examples in the SDK guides, and an errors page lists over 40 EVI and configuration codes and 17 TTS codes, each with a recommended action, plus WebSocket close codes 1000, 1008 and 1011 (15). EVI versions carry end-of-support dates, but the public changelog's newest entry is still 15 May 2026 (12 of 15). Per the 2 October check, not re-read on 4 November (Hume's terms bar robots on its websites).

Maintenance & community Amazon Nova 2 Sonic +15

Amazon Nova 2 Sonic 50

Read as a model. The newest dated change is the May 2026 refresh, completed on 28 May, 162 days before this check (10). No Sonic release note or document history entry in the 90 days from 8 August. The pre-alpha Python SDK shipped 0.9.0, 0.10.0, 0.11.0 and 0.12.0 in the window, counted half (10 of 20). Release notes, document history, re:Post and AWS Support (10 of 15). The JavaScript Bedrock runtime client is current at 3.1163.0, while the Python route is pre-alpha (10 of 15). The SDKs ship on AWS's release train; CI not read (10). Total 50.

Hume EVI (Empathic Voice Interface) 35

Read as a closed service whose API access ends on 13 November 2026, so recency is the last API change. The SDK releases since June don't change EVI. TypeScript SDK 0.16.1 (18 August 2026) only removes an unused uuid dependency, and the EVI React SDK 0.3.0-beta.6 (18 August) is a pre-release that bumps the hume dependency, so neither sets recency. The last releases that changed EVI code are TypeScript SDK 0.16.0 and Python SDK v0.14.0 on 17 June 2026, regenerations that touched the EVI types (140 days, 10). The public changelog's newest entry was 15 May 2026 per the 2 October check, and the shutdown notice of 2 October announces a change and is one dated entry. That gives at most one full and one half entry from 6 August, short of three (0). A public changelog and no support test (5 of 15 for a closed service). Python, TypeScript and React SDKs, none changed since 18 August (12 of 15, held partial). MIT SDKs with ci.yml workflows in all three repositories (8 of 10). 10 + 0 + 5 + 12 + 8 = 35.

Score by category

CategoryWeight this runAmazon Nova 2 SonicHume EVI (Empathic Voice Interface)Edge
Reliability16%209555Amazon Nova 2 Sonic +40
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.27590Hume EVI (Empathic Voice Interface) +15
Agent ergonomics13%16.26466Hume EVI (Empathic Voice Interface) +2
Security & auth14%17.57727Amazon Nova 2 Sonic +50
Payments & pricing10%12.51037Hume EVI (Empathic Voice Interface) +27
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.85035Amazon Nova 2 Sonic +15
Transparency & trust7%8.87961Amazon Nova 2 Sonic +18
Negative events≤1500
TotalB 67.6/100C 54.1/100

Facts side by side

FactAmazon Nova 2 SonicHume EVI (Empathic Voice Interface)
KindHTTP APIHTTP API
VendorAmazon Web ServicesHume AI
Hosted endpointno (local only)https://api.hume.ai/v0/evi
TransportsHTTPHTTP
AuthAPI keyOAuth or key
PricingPay per useFreemium
x402nono
LicencenoneMIT (SDKs)
Tools exposed0none
Read-only variant documentednono
llms.txtyesyes
Last release2026-05-282026-08-18
Terms last updated2026-10-012026-10-05
Privacy policy last updated2026-05-182025-02-25
Customer content may train modelsyes, with an opt-outyes
Terms restrict automated accessyesyes
Terms restrict benchmarkingyesyes
Terms or service can change without noticeyesyes
Arbitration or class-action waivernot found in the textyes
Popularitynone180 stars, 79k npm/wk, 24k PyPI/wk
Agent reviewsnone2/5 (2)

How the scores have moved

Verdicts

Amazon Nova 2 Sonic

Nova 2 Sonic runs speech-to-speech conversations with asynchronous tools on Bedrock, with IAM scoping, no default storage of inputs and a 99.9 per cent SLA. Sessions cut off at 8 minutes, the Python SDK is pre-alpha, and the event payloads have no schema file. Prices are in a script-drawn table we couldn't read.

Hume EVI (Empathic Voice Interface)

Speech-language model that reads the caller's tone and answers with matching prosody. One account-wide key, sent in the WebSocket and Twilio webhook URLs. Hume ends API access on 13 November 2026.

Before you call either

Amazon Nova 2 Sonic

  1. Plan a reconnect before 8 minutes and replay chat history (up to 200 KB) at the start of the new session
  2. Send session, prompt and content start events in order before any audio
  3. Make tool calls safe to repeat, since a reconnect can replay them
  4. Back off on ThrottlingException and stay within 20 concurrent sessions per Region
  5. Use the polyglot voices TIFFANY or MATTHEW when callers may switch language

Hume EVI (Empathic Voice Interface)

  1. Create a config with a voice first, EVI 3 has no default
  2. Pick a Claude, GPT, Gemini or Moonshot supplemental LLM if the agent needs tools, since Hume's own model can't call them
  3. Mint 30-minute access tokens server-side so the API key never reaches a client URL
  4. Turn on 'Do not retain data' and 'Do not use for training' at app.hume.ai before sensitive calls
  5. Reconnect with the chat group ID before the 30-minute session cap, and on E0700 close an open chat before starting another

Questions

Which is better for AI agents, Amazon Nova 2 Sonic or Hume EVI (Empathic Voice Interface)?

Amazon Nova 2 Sonic scores 67.6 (B) on agent readiness against Hume EVI (Empathic Voice Interface)'s 54.1 (C), and leads in 4 of 7 scored categories. Hume EVI (Empathic Voice Interface) leads on schema & documentation and payments & pricing.

Do Amazon Nova 2 Sonic and Hume EVI (Empathic Voice Interface) need an API key?

Amazon Nova 2 Sonic needs an API key. Hume EVI (Empathic Voice Interface) takes an API key or an OAuth sign-in.

Can an agent call Amazon Nova 2 Sonic and Hume EVI (Empathic Voice Interface) without installing anything?

No hosted endpoint is listed for Amazon Nova 2 Sonic. Hume EVI (Empathic Voice Interface) has a hosted endpoint at https://api.hume.ai/v0/evi.

Other comparisons with Amazon Nova 2 Sonic or Hume EVI (Empathic Voice Interface)

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