Hi Ian, I doubt it's relevant, but you'll find the "use compact voice" option under settings->General->accessibility->voiceover. The compact voice is of lower quality, but the trade-off is that it will place less of a demand on system resources.
Absent any kind of specifics in your problem scenario I can only venture to guess at a few possibilities. Sometimes the speaker volume winds up at the lowest possible setting. This could be as a result of human action such as having the phone in your pocket and the volume down button is pressed repeatedly. I also believe that an IOS bug causes this. For example, pulling my phone out of a dock some times results in the loss of volume, or some times it seems to happen for no discernible reason. To resolve this I'll take some action or gesture which should cause the speaker to emit output such as telling Siri to play music. Then holding the volume button should have an affect, which is not the case when there is no active sound output. If you hear the music, but not vo, try toggling it via the tripleClickHome gesture, or if that doesn't bring results press the power button eight times quickly to reinitialize. If you still get nothing other than ringtones emitted from your speaker, you may have a dust particle caught in the headphone jack causing the microswitch to remain open and consequently your hardware behaves as though headphones are connected regardless. When this occurs, you can usually dislodge the obstruction by inserting and withdrawing headphones into your jack about ten times quickly. A vacuum or canned air would also work. The above two problems are not specific to any particular IOS device or firmware level. Since I got my 4S, however, I've been experiencing an annoying intermittent/unreproducable problem that comes in two flavors. Since my hardware and firmware upgrades occurred simultaneously I can't say whether this is specific to the 4S, or if others running IOS5 are seeing this. The two others I know of who are experiencing the problem also use a 4S on the AT&T network, so perhaps the carrier/sim card is a factor? I donno! Anyway, what happens is that I answer a call and can hear/speak to my party for a second or two. Then we both go mute for about ten to fifteen seconds. If the person is not a regular caller, they'll likely assume the call was dropped and hang up. After the long pause, all goes back to normal. The second incarnation is that I do not hear my party, and in fact discover that my phone appears to be completely turned off since activating the mute switch does not cause any vibration. Pressing the power button has no affect, nor does the hard boot sequence (press and hold home and power for ten seconds). My phone becomes a paperweight for about ten minutes, after which I can power it on and the functionality returns to normal. I have not reported this to Apple because I cannot provide a scenario. I recall Sarah A once described how to capture log files, but this problem does not appear to generate a log entry. A friend contacted Apple and in typical fashion, they denied everything and replaced the phone which still has the same issue. So, if you're problem is not covered by the above, perhaps you could post a detailed description with a helpful subject line and we'll be glad to help. Best regards. Geoff ----- Original Message ----- From: Ian McNamara To: Mac OSX & iOS Accessibility Sent: Thursday, February 02, 2012 9:55 AM Subject: Re: iphone 4s problem. Hi how do i change to compact voice? Ian McNamara <--- Mac Access At Mac Access Dot Net ---> To reply to this post, please address your message to mac-access@mac-access.net You can find an archive of all messages posted to the Mac-Access forum at either the list's own dedicated web archive: <http://mail.tft-bbs.co.uk/pipermail/mac-access/index.html> or at the public Mail Archive: <http://www.mail-archive.com/mac-access@mac-access.net/>. Subscribe to the list's RSS feed from: <http://www.mail-archive.com/mac-access@mac-access.net/maillist.xml> The Mac-Access mailing list is guaranteed malware, spyware, Trojan, virus and worm-free! Please remember to update your membership options periodically by visiting the list website at: <http://mail.tft-bbs.co.uk/mailman/listinfo/mac-access/options/> <--- Mac Access At Mac Access Dot Net ---> To reply to this post, please address your message to mac-access@mac-access.net You can find an archive of all messages posted to the Mac-Access forum at either the list's own dedicated web archive: <http://mail.tft-bbs.co.uk/pipermail/mac-access/index.html> or at the public Mail Archive: <http://www.mail-archive.com/mac-access@mac-access.net/>. Subscribe to the list's RSS feed from: <http://www.mail-archive.com/mac-access@mac-access.net/maillist.xml> The Mac-Access mailing list is guaranteed malware, spyware, Trojan, virus and worm-free! Please remember to update your membership options periodically by visiting the list website at: <http://mail.tft-bbs.co.uk/mailman/listinfo/mac-access/options/>