How much phonetic/phonological detail can be captured using IPA alone?

Question

Although spectrograms contain much more detail, I'm curious how far phonologists and phoneticists can go with IPA alone. Can someone provide some examples of narrow, detail-rich IPA transcription for various words in English, Spanish, German, Icelandic, etc.? I'd also be interested in seeing how IPA can capture existing phonetic features such as allophones, etc.

Alternatively, what detail can be denoted in a spectrogram but not IPA?

I've found the following examples of what I'm looking for on Wikipedia:

• pets [pʰɛʔts]
• pretzel [ˈpʰɹ̥ʷɛʔt.sɫ̩]

Answer 1

There are various aspects of disordered speech that cannot be expressed using IPA 2005. This is why, e.g. the ExtIPA chart was constructed. This covers things like:

1. interdental/bidental articulation;
2. whistled articulation;
3. sliding articulation.

IPA Extensions also covers thing like:

1. ʩ - velopharyngeal fricative (snoring);
2. ʬ - bilabial percussive (lip smacking);
3. ʭ - bidental percussive (teeth gnashing).

Another thing is lip rounding. The IPA only supports rounded/unrounded, labiablised and more/less rounding. It does not describe things like compressed vs protruded rounding -- this is implied by the position of the vowels.

Also, with a spectogram you can identify the F1 and F2 frequencies of the different vowels in different speakers and get an accurate representation of where they are in relation to each other. IPA is ambiguous depending on the transcriber (e.g. 〈a〉 can be either front 〈a̠〉 or central 〈ä〉).