WHY IPA ISN'T ALWAYS THE ANSWER
I've had students tell me that they study the IPA system religiously in order to learn pronunciation. Since IPA is subjective, I advise my students to use it as a tool only - not as a definite source. This is because IPA is used to write the pronunciation of a word based on how an individual says the word. Thus, two people can write the IPA for a word two completely different ways... and both would still be correct. But how can that be? The simple answer: dialects.
Someone from New York, for instance, and a person from Ohio would transcribe the word "dog" two different ways. The New Yorker would use the open-O IPA sign (ɔ), while the Ohioan would use the backward lowercase "a" (ɒ). This is because New Yorkers (and most Brits) elongate the "ah" sound and Ohioans don't. Therefore, /dɒg/ and /dɔg/ would both be correct. But, to a non-native English speaker, this can be confusing. And, if the non-native speaker didn't know that IPA is subjective (and not objective), that person would think that one way is always right and the other always wrong. They would also seem to think that the two words would be pronounced differently, rather than almost the same. This is also true for words like "father". The "a" can be transcribed as /ɔ/ or /ɒ/ depending on the speaker's accent. And this, my friends, is the very basic explanation of the difference between British English and American English.
The same confusion is held between the wedge (ʌ) and the schwa (ə). The "uh" sound is the same in these two signs. Native speakers don't usually differentiate between them because they hear the "uh" and know that the sound is as such. But, non-natives don't know this and can be confused. Take the word "umbrella". Depending on the person transcribing, it can be /ʌmˈbrɛlʌ/, /ʌmˈbrɛl ə/, /əmˈbrɛlʌ / or /əmˈbrɛl ə/. If the person hears the "uh" sound clearly, seeming to have a stress or emphasized sound, the wedge will be presumed - and vice verse. However, the most important thing that a non-native speaker needs to realize is that the wedge and the schwa are the SAME sound, no matter what! "uh" is "uh" is "uh". The U-sound in "cut" is the same as the U-sound in "but", is the same vowel-sound in "country", is the same vowel-sound in "above" (both the "a" and the "o" are pronounced like "uh").
So how does a non-native speaker learn the pronunciation correctly if IPA is so subjective? Simple: they learn the native writing or respelling system that is used and found in American English dictionaries!
When a native speaker of American English looks up a word in the dictionary, they are not presented with IPA. What they are presented with is a "spelled-out" pronunciation of the word. For instance, "umbrella" is shown as "uhm-brel-uh"; "cut" as "kuht"; "above" as "uh-buhv". The "uh" is used instead of the schwa or the wedge! No matter a person's accent, that person will know - without a doubt - how to pronounce the word; no matter if they would say "uh" as in the wedge or the schwa, they would know the pronunciation is "uh". Another example of this is the word "road," which is respelled as "rohd". The "oh" is the long-O (as in code, snow, and focus). No matter the IPA symbol that one attaches to this word (/roʊd/ or /rod/), the "oh" tells the reader how to pronounce the word correctly.
And to stretch the point further, what about the word "law"? This word can be pronounced as "lah" or "law", depending on which part of the USA you are located. In IPA, it could be transcribed as /lɔ/ or even /lɒ/. But, in a standard American English dictionary, it will only appear as "law" - with the "aw" showing that the "a" is not the "ah" sound (/lɒ/). And, again, anyone - no matter their dialect - who speaks American English will be able to understand the sound that they are to pronounce.
So what's my point? In short...
Instead of trying to memorize the IPA transcription system - thereby guessing at the correct pronunciation of a word, why not just learn the sounds of each English letter instead? Then, and only then, will you really understand and be able to master the pronunciation of English. And whether or not an IPA transcription uses a wedge or a schwa, for instance, wouldn't matter or be confusing because you'd know the difference between English sounds. Remember, IPA is a good tool but not the absolute! Forget guessing and start learning the sounds of each letter - for that is the way that native speakers of American English are taught to pronounce the many words in their vocabulary. Ever hear of the phrase, "sound it out"? If not, you should find out what it means and use it.
Just a little something to think about! I hope this has been helpful and enlightening. :D And as always, if you have any questions, don't hesitate to ask.