Comparison of Volume (Intensity) in iPad Cases (and a speaker)

In forums and groups of AAC users, iPad cases are discussed a lot. Durability is a big concern for everyone, some people are focused on weight, others on handles/ease of carry, and there is an emphasis on the fact that volume is important. Volume is HUGE. As a speaking person, I can raise my voice to be heard at a windy playground, or in a crowded restaurant---and it's important that Maya can also be heard in those settings. She has the right to be loud! We've always used an iAdapter case on her talker (or mini, as she has now) because it was the only amplified case on the market---and that amplification is essential. (There is now another amplified case available, but at $395 I'm not buying it to test out.)

A lot of new users aren't able to buy an iPad, an app, an a very pricey amplified case, and I often see "we're using xyz case right now but may get an amplified one in the future." Some people use their case as-is, others use an external speaker (which plugs in to the headphone port on the iPad) or a bluetooth speaker (which works wirelessly). Recently I bought the ION Clipster bluetooth speaker to use with Will's talker, when needed, and was surprised by the sound quality and volume (in a good way). Since I have a variety of cases at my disposal, it made sense to do a quick analysis of volume, so that users who are debating different options have a bit of data.

Products: The products tested were: the Gripcase, the Otterbox Defender case, the Griffin Survivor case (with back speaker flap removed), the iAdapter mini case, the ION Clipster bluetooth speaker, and a plain (uncased) iPad.  Decibels were measured using the "Decibel 10th" app.

Method:
Set-up: The iPad being tested was positioned 25 inches from the data-recording iPad, with speaker facing towards the data recorder. The internal volume of the iPad was set at its maximum level.

Test language: Each iPad ran the same sentence set ("My name is Maya. I can do it! This is only a test.") on the same voice (Katherine-American, fast rate, very high pitch) in the same app (Speak for Yourself).  On the second night of testing I also ran the same sentence set in the app Proloquo2Go, after several users reported feeling like the P2G app runs louder than SFY.

Trials: Each iPad was run 3-5 times consecutively to ensure that the data was consistent. The decibel number recorded was the "average" intensity displayed after running those sentences. The entire experiment was conducted within a  short timespan (less than 10 minutes) on one evening (so ambient noise should be discountable) and then completely repeated the subsequent evening.

Data:

Case/Speaker	Average Intensity (dB) 9/5/14	Average Intensity (dB) 9/6/14
iAdapter mini case-HI setting	93	93
iAdapter mini case-LO setting	91	91
ION Clipster Bluetooth speaker (at full volume)	91	91
Gripcase	76	80
iAdapter mini case-OFF setting	78	79
Otterbox Defender case	76	80
iPad without case	76	80
Griffin Survivor case (SEE NOTE #2)	76	80

Important notes:
1. I wouldn't put too much stock in the accuracy of these decibel readings. The app seemed to work consistently enough to get a main idea and notice trends, but I had no way of checking the accuracy of the actual dB readings.

2. The Griffin Survivor case typically has a flap that covers the speaker. Two weeks ago I became very frustrated that the kids could never hear me when I used that device for modeling, and I cut the flap off with a pair of kitchen scissors. I am 100% sure that the Griffin Survivor would be quieter than all other things on this list if the case was actually intact.

Interpretation:

1. The iPad without a case, the Gripcase. the Otterbox Defender, and the Griffin Survivor (with back flap removed) all tested at exactly the same level, although if the Griffin case was intact (see above note #2) I anticipate it would have been quieter than the others. The iAdapter case in the OFF setting appears to be at close to the same dB level, although the reading differed slightly from one night to the next.  Bottom Line: If you are planning on buying one of these cases the volume provided by the case shouldn't be one of your decision-making factors---they're all the same. You will definitely need an external or bluetooth speaker if you are using one of these cases in conjunction with an iPad as a communication device. This level of intensity is not enough to be reliably hear in crowded or outdoor situations.

2. The iAdapter case on LO setting tested equal in intensity to the ION Clipster speaker, when the Clipster was at full volume. When the iAdapter is turned on HI, it was the loudest of all items tested. Interestingly, the voice quality between the iAdapter and Clipster are different, even at the same intensity (volume) level. The iAdapter voice sounds a little more thin, or tinny, and the Clipster voice has more depth to it. This clip shows the sound difference:





Bottom Line: These are both good options, although they differ in a few respects that may make one preferable to the other on a case by case basis: The iAdapter offers the most volume, the Clipster doesn't get as loud but has a richer sound. The iAdapter speakers are built into the case, the Clipster has to be attached to either the case or the AAC user.


3. The ION Clipster's volume reading had a significant change (+5dB) depending on where the speaker was aimed (away from the listener/toward the listener). Bottom Line: If you use the Clipster across multiple settings, be mindful of which direction the speaker is facing. This is particularly important if you attach the speaker to the back of a case that could end up in the user's lap (circle time at school, carseat, stroller), which will aim the sound downward and possibly muffle the speaker.

4. Several users of Proloquo2Go mentioned to me that the amplification aspect of a case might not be as important to P2G users as it is to SFY users because the P2G voice is louder. Since I own P2G I ran the same sentence set and found that the P2G app actually is softer (-3dB) than Speak for Yourself. The P2G voice is a bit richer, and the pauses in speech feel more natural, so I wonder if maybe the perceived "louder"-ness is actually just an increased ability to decipher the speech from further away due to tone and speech pattern, because it actually measured as quieter. Bottom Line: Proloquo2Go tested as softer/less intense than the Speak for Yourself app, indicating that volume should be an important part of case selection regardless of app used.


Disclaimer: I have no affiliations to any of the cases, speakers, or apps mentioned in the above post. This was done independently and isn't endorsed by anyone. If you do a similar experiment and get different results, let me know---more (well done) data is always better!