Feeding audio signals into phone lines

From a technical perspective, what it sounds like you want to do is actually to inject your speech synthesizer's output into a phone call. That means injecting the synth output into the phone you are using, replacing the signal that would normally come from the mic in the phone handset or in your speaker phone.

This perhaps a better way to phrase your question and may get you better answers from people. Am not sure about this being the correct news group, though.

So to accomplish what you want to do, I suggest that there would seem to be two ways to go at it.

One: you start with a telephone that allows a headset to be plugged in. The you wire the synth voice output to the microphone wires of that headset. There will be likely some impedance issues to look at and how to control the volume. And you need to be careful of not damaging your synth unit.

Your speaker phone system may support plug in additional components like a second microphone.

Two: place a small speaker wired from the voice syth directly over the phone's normal voice input (read what one talks into).

Basically you are trying to replace the phone's input signal from the handset with your synth's out put. It would be my guess that there are voice synth devices that have this interface included with them.

Hope this helps some. Let us know how this goes.

ClamRake

I think what you need is a "Telephone patch" which can be a pro model like this:

a homebuilt impedance matcher to match the out put of the speen synth equipment to the 600 ohm phone line. The Ramsey unit is ony $70 but needs to be built.

More sites:

I don't know if this is the proper newsgroup in which to post this

Hi,

I'll try to answer your questions below. At the bottom of this post, after my signature lines, I will list various assistive technology "Tech ACT Projects" where you may find additional information.

This newsgroup is an entirely appropriate place for your query. There are, of course, newsgroups dedicated to CP and to AT where you might find more help. But many people here have an interest in assistive technology. At least one is wheelchair bound as well.

You can use a simple audio transformer and volume control, connected to the microphone input of the telephone. There are keyboard - to - speach devices available with an interface for connection to a phone line. More on that later.

Toshiba has developed a product which makes it possible for people with CP to use a mouse. A reflective, silver dot is affixed to one's glasses. An IR light is mounted to the top of the monitor. The user points the dot at the screen by looking at what he wants and then clicks a button. The PC reads it as a mouse click wherever the red dot is pointed.

There is an article about this in Newsweek's online magazine.

this technology may enable you to utilize Windows. If so it will open a wider window for you. Hope so.

On to your original questions:

Most modems are designed to hang up if they don't hear carrier signal from a modem on the other end of the phone line. This can be overcome by placing a phone off hook on the same line but it doesn't solve the presenting problem -- making synthasized speach work with the phone.

I'd be happy to help you locate an interface device if you like. I'm not interested in selling you anything but I'd be glad to make a few calls to companies that offer AT hardware.

Way back in Windows 3.1 days I wrote some software that used the text-to-speech software that came bundled with the 16-bit SoundBlaster soundcards as well as another low cost ($25 per licensee) commercial text-to-speech package which had excellent voice quality. The software was intended for people like you with speech problems. The users were a mix of those with CP, ALS and other maladies that caused speech problems.

Initially, I wrote it to use a direct connection to an internal speakerphone modem because the sound was very clean that way but I got feedback from several users that they preferred to use it with an external speakerphone modem in front of a PC speaker because that sounded more natural with the normal background sounds. Creative stopped bundling their TTS software and the other company got gobbled up by Lernout & Hausbie and disappeared along with them.

My software included home automation functions and sold for $180, including the TTS license, but is no longer available.

There are numerous speakerphone modems available but I don't know how many of them have DOS drivers. These days most of the external ones have USB connections and expect Windows.

If you can find a speakerphone modem with a serial interface and DOS drivers, it is, by far, the easiest way to accomplish what you need.

You probably already know that the commercial companies selling this type of equipment have exhorbitant prices (despite being subsidized by the government).

I won't do the searching for you but, if you find some speakerphone modems, I'll look at them to see whether they will work for you.

BTW, I'm not sure anyth>I don't know if this is the proper newsgroup in which to post this

I forgot to ask - what brand, model is your current modem? If it is a speakerphone modem, all you may need is a connection from your soundcard line-out to the modem line-in jack.

I think I may still have one internal Supra speakerphone modem with DOS drivers. I'll have to dig through some old junk boxes and also see if I still have the installation floppy disk. If so, you are welcome to them.

| Anyway, my question is: What is the simplest (and least expensive) | way to feed an audio signal into a telephone line? | | My specific application is as follows: My speech is next to | impossible to understand due to cerebral palsy. Therefore, I often | use a speech synthesizer to communicate with people, including | people over the phone. Currently, to "speak" over the phone, I | depend on the microphone in a conference phone to pick-up the sound | waves coming from the speaker in my speech synthesizer. While this | configuration works, the quality of the sound that gets transmitted | over the phone line is less than satisfactory. This is why I am | seeking a direct way to input an audio signal into a phone line. | | When making suggestions on how to accomplish what I want, please | keep in mind that I don't use a Windows computer with a sound card. | I still use a DOS computer, mostly because I can't/don't like using | a mouse.

Ignoring the legality of connecting directly to the phone line, likely the best way (in the sense of highest quality audio) to accomplish this is with a 600 Ohm 1:1 audio isolation transformer (possibly still available at Radio Shack). Connect one side of the transformer in series with an

0.1uF capacitor to the phone line. Drive the other side of the transformer with the speaker output of a small audio power amplifier. (A 1W unit suitable for "bookshelf" speakers is fine. You don't need a lot of power, but often you do need more than is available from a line output. Having the volume control and possibly some tone adjustment is useful too.) Connect the output of your speech synthesizer to a line input of the amplifier.

I've tried a number of commercial couplers over the years and none come close in quality to the above approach.

Dan Lanciani ddl@danlan.*com

I think he was using a bigger one made by Logitech. Both MS and Logitech have discontinued these but there are (or were) some similar devices available from some of the assisted living companies but most are USB/PS2 and need Windows or a Mac.

"BruceR" wrote:

OK, I found the speakerphone modem, installation instructions, and software (including DOS voice and fax software). If your PC has an ISA slot, I think this will do what you want. It was working fine when I removed it but that was a few years back. All I need is an address to ship to. You may need someone with a Windows machine with JavaScript active to help you. Go to my web page at...

and send me an e-mail using the "Contact:" link at the top-right of the main page.

It's a Diamond Multimedia SupraExpress 56i SP. It requires an ISA slot. In addition to phone jacks it has a microphone jack and a speaker jack. I do not recall for sure but think it needs amplified speakers (i.e. the speaker jack is really Line-Out).

You can read about it here...

Does your PC have a soundcard? If it's a SB16 or later, the TTS software from Creative will work with it but, as best I recall, this required Windows.

Something like this might meet your needs, assuming you can wire up your speach synthesizer.