Thank you for your comment and I appreciate your concerns. I suppose that most products, if used improperly can impose some degree of danger and as always proper care should be taken when using anything. According to the instructions, the BarkstopCD should be used in short bursts. If you just let the CD run, at high volume levels, you could possibly cause damage but then if used in this manner, the CD would be completely ineffective as a barking deterrent. Remember, the dog must establish the association between his barking and the short corrective bursts. As far as the "Good Doggies," yes, they would probably hear the tones also, however, note that high frequencies are very directional. If your speaker is pointed toward the offending dog, and the "Good Doggies" are somewhat off-axis, they would hear much less of the tone. Hopefully, anyone who has invested in audio equipment that is capable of causing physical damage, would also have some degree of expertise in operating said equipment in a safe manner. To close, I can say that personally, as it pertains to safety, I would feel much better about using this product than a shock collar.