No, I haven't lost my mind, but rather a short discussion of phonetic crossbill calls ! I get many references in emails describing crossbill calls in the field using phonetic descriptions. Most existing phonetic descriptions in the crossbill literature, other than those by Magnus and Sound Approach, are errant or misleading in my opinion, particularly for Loxia scotica. They also may not reflect the 'current' evidence either. Actual audio recordings are preferable, however the following may offer some clues in separating Parrot Crossbill from Scottish Crossbill in the field.
Flight Calls are a distinct "Choop" or "Chup", emphasis on the "oo" or "u". These can also sound 'flutey' (a term often wrongly used to describe Scottish flight calls) due to a pronounced harmonic that is often present ( and which can make them appear on sonagrams like published Scottish flight calls). Birds may also give a more subdued "tip, tip, tip" call when in 'cryptic' flight (similar to those given by Bullfinch). They sometimes give these on release after being captured and ringed. These can appear as single descending streaks on sonagrams.
Excitement calls are a lower pitched (than flight calls) 'cluck' reminscent of a Blackbird alarm call, or more closely a Jackdaw (and between the two in 'pitch' and timbre). Aurally, Parrot excitement calls sound very similar to Common Crossbill EcA ( or "British" ala Sound Approach) and it takes much experience to separate them by ear in the field. In such cases a look at the bill should help diagnosis, but not always it would appear !
Recent evidence that I have collected and matched with biometrics shows intermediate billed (Scottish) give a 'di-syllabic' flight call sounding as a "t-reep" or sometimes a 'lispy' "th-reep". This is much higher pitched than Parrot flight call and in fact can not be confused aurally with ANY commonly occuring Loxia in the UK ! NB. THESE CALLS ARE DIFFERENT FROM THOSE THAT HAVE BEEN PUBLISHED !
Scottish excitement calls are much more 'hollow' than Parrot Crossbill, and sound like a "tonk, tonk" or "tunk, tunk" - I think it sounds more stacatto (abbreviated) than Parrot and timbrally similar to wooden claves or woodblocks being struck (for any would be percussionists out there !). In the field it is VERY similar in tonal and timbral quality to Common Crossbill EcE or "glip" excitement call, especially if the harmonics are less pronounced ( which makes the call look very similar on a sonagram too !). This is a RARE call, by far my rarest recorded Crossbill Excitement call, suggesting this call, like the flight call, may be in a state of flux - time will tell.
One word of caution. Often people describe large-billed crossbills giving very 'deep calls'. In cases like this, assuming they are correct, they are describing Parrot Crossbills as both Scottish flight and excitement call are higher pitched than Parrot, and typically much more like those for Common Crossbill. It is worth reiterating that 90% of photos I am sent or see on the web of presumed 'Scottish Crossbills' are in fact actually Parrot Crossbills (in my experience) ! My advice: leave the camera at home, buy a mic and recorder, think about the above, and learn about the vocal dialects of the crossbills in your area.