Not only is the tone loud enough to overcome my severe hearing loss, but the flashing lights and the bed vibrator make this alarm impossible to ignore.

Most of these Sonic Boom and Sonic Alert clocks will wake up heavy sleepers with no problem. However, I am hearing impaired and, without my hearing aids in, I can't even hear a regular clock's alarm when I am asleep due to the high pitch. My phone's alarm goes unheard as well. I HAVE to have a clock that's not only loud but has variable tone because my type of loss is in the high pitches. If a clock or any device has a high pitched sound, I can't hear it (Store theft alarms, microwaves, cat meows, etc.) I had Sonic Alert's The Skull with Bone Crusher Bed Shaker and it was great but broke after a year and I had to get a new one which broke again after about a year of not too constant use. I decided this time to get the Sonic Bomb with Super Shaker - SBB500ss. To my surprise, Amazon says I bought this clock in 2010! I have no idea where it went or what happened to it but I bought another one anyway.

This clock is very lightweight and doesn't take up a lot of space. It has a large display and a battery back up. It has both volume and tone adjustments which are both absolutely a must for me. I have it set to the lowest tone and I can hear that just fine. I also have it set to the loudest volume setting which would probably scare the pants off of a person with perfect hearing but doesn't bother me when I hear it except to know I have to get up. There are nice features like the ability to adjust snooze time from 1-30 minutes and the ability to select the alarm duration from 1-59 minutes. I set the snooze for 5 minutes and the alarm time for the full time. I can always turn it off early.

Setting the clock is a little different. You can push a button to make the time go fast or slow. That is, rather than setting the hour, then the minutes, you have to push the button and let the clock cycle through every hour and minute. But it's very fast and, when you get close to the time you want to set the alarm, you switch to the slow button and get it just right. Not an issue, just different from the norm.

The clock has a bar on top which blinks red and other lights that also do the same when the alarm does off. It has a different sort of alarm pattern. It beeps three times, stops, then repeats until you tap the sleep bar or turn it off. Other clocks continuously beep until they're turned off. This doesn't affect the clock's power to wake me up but again, I am just so used to the Skull that I had to adjust to the new alarm pattern.

The bed shaker is effective. I usually put it under my pillow or in my pillow case when I use it. I can feel it quite well and even hear it because it has the pitch that my ears pick up. I generally only use the alarm but when I NEED to be sure I get up, I use the shaker and alarm and also set my Fitbit's silent vibrating alarm on my wrist for good measure.

This alarm is loud but not quite as loud as the Skull. It is certainly plenty loud enough for heavy sleepers and even for someone like me who has hearing loss. Setting the alarm, shaker or both is as easy as sliding a button up on the side of the clock.

This clock is a great choice for heavy sleepers and those who have hearing loss. Even if you can't hear the alarm, the shaker will do the job of waking you. The lights are a plus especially if the room is dark or dim. I like the clock but I am not sure of its durability. I guess time will tell but at this point, I feel confident that this will wake me up with just the alarm or the shaker. If you need a clock that's loud and also that has adjustable tone, this one is a good choice. The ability to adjust the tone makes all the difference in the world to people with hearing loss in either upper or lower pitches. I can not hear the clock at the loudest setting when I set the tone/pitch to the highest level. It's above my ability to hear just as birds are. But at the lowest tone, it's enough to wake me even out of deep sleep.

I am going with 4 stars because the Skull was a bit louder and I think the way you need to set the clock is a bit more work than setting the hour and minutes separately. But those are small things compared to all the good features this clock has. It will wake almost anyone up!

This clock is getting rather mixed reviews and I was a little worried when I bought my first one about a year ago. I bought it for my son, who was a senior in high school. He slept through all of the alarms that I bought at Wal-mart for him. He would then be late (or not go) to school and the principal would call me to ask where he was. (I swear the principal had me on speed dial!) After I gave my son this alarm he never slept through his alarm again. He did leave school early on numerous occasions (and the principal kept me on speed dial) but an alarm clock can only do so much at helping with parenting. (He graduated, thank God, and uses the alarm to wake-up for work now.)

My son's alarm has worked perfectly since the day it arrived, so I had no qualms in deciding to buy one for myself last April. I am hard-of-hearing and I like the vibrating disc that goes under my mattress. It wakes me up right away. I don't even put on the noise--just the vibrator. It works great! It has gained 2 minutes in 5 months. I think people should READ THE DIRECTIONS and set the switch on the back for USA electric currents!

My son-in-law and daughter sleep through their alarms all the time--even when they have 2 or 3 of them set! I gave them my Sonic Bomb alarm clock 3 days ago and he has woke up on time every day since!
That is why I am purchasing my third one today. I need another one for me. These alarm clocks are great and I highly recommend them to heavy sleepers, hard-of-hearing, or even profoundly deaf people.
There are some features the clock has that are not mentioned in the description of the clock:

1) It has battery back-up--so when the electric goes out (ours goes out about 15 times a year) the clock still keeps time.

2) The alarm has the ability to be on just noise--really loud annoying beeping, which can be adjusted for loudness and tone (for hard-of-hearing people who hear some tones and not others)Or you can put it on just vibrate--for people like me who don't like to wake-up with adrenaline pumping through my body. Or you can really juice it up by putting on the noise AND vibrate your bed, which my son and son-in-law both use to wake-up.

3)It also has flashing red lights that go off when the alarm does to help people wake-up.

I do not have anything bad to say about the clock. I highly recommend buying one. Just make sure to read the directions pertaining to the switch on the back about setting it for which country you will be using it in.

August 9, 2012 Update: All 3 of our alarms are still working great!

February 9, 2014 Update: All 3 still working fantastic! The best alarms we have ever owned!

August 19, 2021 Update: My alarm is still working great!! Keeps great time and the vibrator is still functioning perfectly!! Wakes me up everytime. I assume my married kids' alarms that I gave them are still working or they would have asked me where to buy a new one, Lol

UPDATE: I've come to the conclusion that the vibrating module is creating a significant amount of static electricity buildup. So much so that it caused the alarm to reset multiple times, and with the battery inserted it would bug out the display and fail to read a valid time. This would require me to pull the battery, this losing my alarm settings. It would also make me acquire so much static in my sleep that I could see the arc jump when turning my light switch on in the dark. As soon as I removed the vibration module from under my bed, no more issues occured. Keep this in mind. I may have a faulty unit, or the design itself may be flawed (I am leaning towards the latter rather than former). I will be keeping the alarm because it still is very loud, but it will lose a star from my original 4 star rating because of this flaw, unless I fail to wake up from it or the unit dies before one year of use, in which case it will get only 1 star. For now I still do recommend it for heavy sleepers, but I will be casually looking for an alternative brand to try out in the near future.

If you're a heavy sleeper, and I mean heavy as you are mistaken to be dead you sleep so heavily, the buzzer on this alarm alone will wake you. Combined with the vibrating module underneath you and you better have a necromancer on call in order to send the spirits back to text that you'll sure awaken as well.

If this thing doesn't wake you up at the time you set it for, I'm afraid you might want to look into sourcing a live-in nurse to wake you with a shot of adrenaline as a solution.

The only complaint I have is the lack of a day of the week setting so that it would only set the alarm for M-F and have alarm 2 set for weekends and at a later time only using the vibration for a less jarring arousal from sleep. So long as you remember to set it, it will surely get you up. An additional thing to note is that while it does have a battery backup with a 9V, it WILL NOT operate on battery power. It is only to hold the settings in memory so that if you lose power during your sleep and regain power, you will still be alerted at your alarm set time, so long as AC power is restored before then. It would be nice to at least power the clock/buzzer and just bypass the vibration on battery. These two minor complaints are the only reason it gets a star deducted. It's a no frills, stupid alarm clock which is what I want. Not some fancy thing connected to the internet telling Amazon when I go to sleep and when I wake up to pee or listen to me snore. Safe AND effective!

Ever since I got my C-PAP several months ago, I've been sleeping like the dead. By which I mean that I sleep through all of my phone's alarms, which used to wake me up from my fitful, cruddy (lack of) sleep.

That entire setup is your first clue, dear reader, that I am old. I am an old man who does not like waking up in the mornings. Mornings suck. If I ever hit the lottery, I will wake no earlier than nine in the morning. The early bird gets the worm, you say? Yes. Well, the second mouse gets the cheese.

On the plus side, these days I wake feeling refreshed--like I actually slept.

On the downside, sleeping through my alarms wasn't great for that sucky part of adult life called "employment." My boss is somewhat forgiving, but she's not going to change my start time to, "Whenever this guy shuffles in on any given weekday." Trust me. I've tried. She's not having it.

So, I ordered an alarm clock that I figured would do the trick. This little gizmo. With the lights and alarms and vibrations.

If it's been awhile since you've set a digital alarm--one that isn't your cell phone, I mean--you may need to read the included instructions. I know I did. (I TOLD YOU I'm old. Sit down, young'uns, while I tell you the terrifying tale of Growing Up Without WiFi. Oooh, spooky!)

The directions helpfully explained what all the buttons do, and when, and how to make this alarm clock do what you want it to do. Overall, setup was quick and easy, including turning on the alarms I'd just set.

Then I tested the alarm.

Holy. Cow. Am I glad there's a way to adjust the volume on this thing. I had it set too high for the test run. It wasn't like my face melted or anything like that--this alarm does NOT go up to 11--but it was close.

My wife was downstairs and she heard this alarm over the TV.

A neighbor who happened to be outside wondered if I'd gotten a new kitchen timer.

Somebody from NASA contacted me to say that somebody on the International Space Station had requested that I shut that thing off already.

Nifty features:

* I can set two alarms. Because sometimes, I just want to turn off the first one and lie in bed for awhile. It's nice to have the second go off to tell me that, no, I really do need to drag my butt out of bed and do work-type stuff.

* The display brightness is dimmable, in case you care about the glowing-red numbers interfering with your sleep.

* Bright, pulsing lights that, despite being very effective on me, do not in fact wake the dead. (I'm qualified to say this, as I live near a cemetery and, so far, no undead visitors complaining about their eternal slumber being disturbed.)

* A plastic disc to put between the box spring and top mattress. Do you sleep on your back? FREE BUTT MASSAGE AT "NO THIS IS TOO EARLY" AM. Do you sleep on your side? Sorry about your bruised ribs. Do you sleep on your stomach? Don't. Just...don't. The power of the vibrating disc will bruise your navel.

Fortunately, most of these features are optional. I can tell the alarm to not bother with the flashing lights, and I can skip the Vibrating Disc O' Doom. However, I usually need one or both of these options, so I keep them on and accept the fact that I will be startled awake five days a week.

As for my statement that this alarm works "most of the time."

When I have to take a full dose of Benadryl, this alarm doesn't work. This is why I can't take the full dose. If I sleep through this ridiculous, loud, vibrating, flashing monstrosity of an introduction to the morning, I will sleep through literal axe murderers making their way through the house at full volume. And nobody needs that in their lives, especially first thing Monday morning.

Buy this alarm if you really need to be awake at a specific time. Five stars because the alarm clock did not come with the Benadryl and, therefore, cannot be blamed for that unfortunate situation.