Continuity mistake: After the chipmunks have performed 'Witch Doctor' at the Jett Records presentation, everyone starts to applaud and in one shot we see a huge net-load of balloons fall from the ceiling, onto the dance floor (which has been made to look like a huge vinyl record.) However seconds later we hear the DJ to tell everyone to start dancing and there is an overhead shot of everyone moving onto the same dance floor; only now there is not one single balloon in sight and there is no way they could have all disappeared off the dance floor. (00:51:25)
Continuity mistake: When Claire walks over to the signing table that Dave and the chipmunks are sitting at (after their stage performance), she bends down to take a photo of them and Dave holds his hand up and forms a 'peace' sign with his fingers behind the chipmunks. But in the following reverse shot the chipmunks cannot be seen in front of the peace sign, when they should be visible. (00:52:10)
Continuity mistake: In the scene inside the house that Uncle Ian gave the chipmunks, Alvin has foam darts on three air-pump launchers. He fires all three of the foam darts from the launchers; and we see him standing on the table with the three launchers and the three attached air-pumps, nothing else. But in the next shot suddenly all three of the launchers have a foam dart readily attached to them! And in addition a large pile of foam darts has appeared on the table, behind Alvin. (01:00:30)
Continuity mistake: Inside the house that Uncle Ian gave the chipmunks, the chipmunks are all playing with the new toys they have received. Simon and Theodore are on a trampoline and Alvin is playing around with foam darts. In one shot we see four foam darts shoot across the room in succession - however there are only three dart launchers. (01:00:30)
Continuity mistake: When the chipmunks start practicing for the first time with Ian, Ian gives Simon "cooler" glasses that he should use it from now on. However, in their tour shots he's still using his old glasses. Much later in the movie he is also seen rummaging through a desk cabinet for his his old glasses which he found to be already bent. (01:01:50)
Factual error: When the Chipmunks are going on tour and all of the cities are listed, it says that they're going to "Phoenix - NV" however it's clear they are in Arizona not Nevada, so it should have said "Phoenix - AZ." (01:02:40)
Continuity mistake: In the scene where the chipmunks are on the set of the Crunchy Nibbles advert, they are each standing in front of a bowl of the nibbles. But they are completely knackered, and Theodore falls forward into his bowl, causing nibbles to spill all over the table. However in the following shots the amount of nibbles around the bowl on the table is inconsistent. (01:03:20)
Continuity mistake: When the chipmunks are in the recording studio they are too exhausted to sing their song, so Ian comes in with plastic cups of coffee for them. Above the chipmunks heads is a large silver microphone - during this whole scene the microphone alternates from being just above their heads to being much further above their heads. (01:04:00)
Continuity mistake: When Uncle Ian is telling the chipmunks in the dressing room that they need to lip sync along to their song, there are alternating shots, and one of them is Ian and Alvin talking whilst being reflected in a large vanity mirror. However in the shot where Alvin turns around on the vanity table and tells Simon and Theodore they 'have to lip sync', Ian is not reflected in the large mirror, then in the next shot he has appeared back to where he was standing and is once again reflected in the mirror. (01:12:55)
Revealing mistake: When the chipmunks are singing 'How we roll' there is a shot of Ian with some people in a private room. The music continues to play as they listen and the stage is reflected in the glass, how ever the chipmunks, back up singers, dancers, instrument players and audience are missing. (01:17:40)
Continuity mistake: Towards the beginning when Dave leaves the record label (after he steals the muffins), downstairs you can see a girl in a pink top, a delivery guy and a black guy in beige boots. The girl in the pink top passes Dave, then it cuts and you see her in front of Dave. Then it cuts again and you see her behind Dave and going around a corner. Also, the guy in the boots does the same thing a few times. And the delivery guy comes up close to the shot in the end, then they show him again just getting close.
Continuity mistake: In the end, when Dave is chasing Ian, we see many headlights behind him. However, once the chipmunks hop up and Dave slams his brakes, we see no lights and no cars pass him. Also, the whole time they are talking, no cars pass again. When Alvin steers the car there are all kinds of cars again flowing both directions.
Continuity mistake: The pumps of chocolate sauce in the chipmunks' coffee disappear too quickly for them to drink it all.
Continuity mistake: Dave captures the chipmunks in a pot, but right before the pot touches the counter, the chipmunks are not under the pot. They are not animated in it.
Visible crew/equipment: When Dave and the chipmunks are talking in the living room on Christmas morning, you can see a crew member reflected on the lamp shade.
Answer: No it isn't his voice.