One of our club members made a telephone amplifier so I searched and combined several ideas . The prototype done in pecan was not loud enough maybe due to thickness . 

The second done in Bradford pear is thinner and is the loudest. When I turned I left the tenon on so I could use it to glue into a backboard so it will not roll. Thought of maybe a flat on the bottom instead but that may reduce the resonance . 

So the last one I cut slots in and the sound is almost as loud but because of the slots there is a smoother sound.

Never heard of this but what a neat idea. Thanks for sharing Gerald. I can see where thinner would work better.

 

Steve

That's on my list. But, it's gonna have to be flat work. 

I like it but I would need to get a phone for it to work.

2 hours ago, HandyDan said:

I like it but I would need to get a phone for it to work.

Yep, that might help.

2 hours ago, Gene Howe said:

Yep, that might help.

Gene google phone amplifier and you will get many hits. There is one cool one with a horn  done in flat work.

PHONE AMPLIFIER

Wow! Thanks, Gerald. That link has some great ideas.