If you want to be a piano tuner, you *must* learn to hear beats. The very essence of aural tuning depends upon the perception and control of beats. The truth is, you can already *hear* them but have not yet leaned to recognize them. If you start tuning using an electronic device and tell yourself that you *can't* do it by ear, the longer you use the device, the more resistant you will become to doing what is absolutely essential.
Electronic devices can do well but anyone who knows how to tune well by ear will tell you that they are not perfect. If you depend entirely on an Electronic Tuning Device (ETD), you will never master tuning and your tunings will always be mediocre at best and quite flawed in many cases and you'll never know what to do to fix anything your customers find to be faulty. Word will quickly get around that you don't really know what you're doing and your clientele will be severely limited.
I regularly tutor people who claim they can't hear beats. After a 90 minute session, they leave being able to do so. It isn't as difficult as you may think. I will be giving private tuning tutoring at the next Piano Technicians Guild Convention in Kansas City, June 20-24, 2007. If you want to be a piano tuner, the best advice I or anyone could ever give you is to join PTG. See www.ptg.org.
I will also give the same session to a group at our regional seminar in Madison, WI, October 4-7, 2007. I also give private tuning tutoring here in Madison. Where is LSC? If you tell me, I may be able to suggest someone closer to you.
Also, I have newly revised a long instructional paper which you may request by e-mail at Billbrpt@aol.com. This paper explains in every detail first how to perceive beats and how to tune the midrange of the piano by ear. You and anyone else are encouraged to send for it but you should also get some help from an experienced piano technician, preferably a PTG Registered Piano Technician.