W3C home > Mailing lists > Public > w3c-wai-ig@w3.org > April to June 2017

Re: Screen Readers | Rate = Words Per Minute

From: Christophe Strobbe <strobbe@hdm-stuttgart.de>
Date: Thu, 11 May 2017 17:54:35 +0200
To: w3c-wai-ig@w3.org
Message-ID: <4c294dcc-97da-2732-a6e9-73de41835943@hdm-stuttgart.de>
Hi,

On 9/05/2017 16:51, Wright, Isaiah wrote:
> (...)* *
>
> I have access to NVDA but the rate is by percentage instead of words
> per minute. Is there a chart out there that translates rate percentage
> into words per minute?
>

If you really need conversion formulas, here is the best I found for NVDA:

(nvdaRate / 100) * (maxRate - minRate) + minRate = wpm (with with
maxrate = 390 and minrate = 80)
This formula assumes eSpeak; it may not be a very good approximation for
other TTS engines.

For Orca, I have used the following two formulas:
(1) wpm = eSpeakNormalRate + (eSpeakNormalRate - eSpeakMinRate) * (r-50)
/ 50
(2) wpm = eSpeakNormalRate + (eSpeakMaxRate - eSpeakNormalRate) * (r-50)
/ 50
where:
* r = Orca’s speech rate value
* eSpeakNormalRate = eSpeak’s normal speed on GNOME; here = 160
* eSpeakMinRate = eSpeak’s minimum speed on GNOME; here = 80
* eSpeakMaxRate = eSpeak’s maximum speed on GNOME; here = 310

The first formula is used for Orca speech rates lower than 50; the
second is used when Orca's speech rate is 50 or higher.

Warning: I have not checked the accuracy of these formulas since April 2014.

Best regards,

Christophe Strobbe

>  
>
> Cheers,
>
> *Isaiah M. Wright*
>
> Usability Research  | Integrated Channels & Experience
>
> 440 S. Church St., Charlotte NC 28202
>
> T + 704 444 4694  |  isaiah.wright@ally.com
>
> image001.gif
>


-- 
Christophe Strobbe
Akademischer Mitarbeiter
Responsive Media Experience Research Group (REMEX)
Hochschule der Medien
Nobelstraße 10
70569 Stuttgart
Tel. +49 711 8923 2749

“I drink tea and I know things.” 
Falsely attributed to Christophe Lannister.
Received on Thursday, 11 May 2017 15:55:13 UTC

This archive was generated by hypermail 2.3.1 : Thursday, 11 May 2017 15:55:15 UTC