Voiceless glottal fricative
This is a standard voiceless glottal fricative. It is also comparable to a devoiced vowel. The symbol is /h/. In Romance languages that do not pronounce this sound, and English, the letter's name is usually pronounced with a palatal or velar sound (Spanish /aʧe/, French /aʃ/, Italian /aka/, Portuguese /aga/, English /eʧ/). In Germanic languages, the name is usually pronounced /ha/.
Germanic languages
English
In all stages of English, the letter h in the initial position (in a syllable of Modern English, though most of the time /h/ comes at the beginning of a word, notable exception is behind). In Anglo-Saxon, an h after a vowel would be /x/ or /ç/ depending on the location of the vowel. The symbol h is used in many digraphs without the /h/ pronunciation, such as ch /ʧ/, th /ð/ or /θ/, rh /ɹ/, ph /f/, sh /ʃ/, wh /ʍ/, and hn /n̯/, hr /ɹ̯/, and hl /ɬ/ (the last three are from Old and Middle English).
Other West Germanic Languages
High German, Dutch, and Low German also commonly use the symbol h to represent the sound /h/, which is also fairly common in the language.
In High German variations the digraphs sch /ʃ/, tsch /ʧ/, ch (Old High German hh /ç/, and ph /f/ are all used without the /h/ sound but spelt with the orthographic 'h.
Old Norse and Icelandic
The symbol h was/is used to mark devoiced versions of normally voiced sounds (like in Anglo-Saxon). Otherwise it is used to represent the normal /h/.
Danish, Norwegian, and Swedish
These three use the same symbol to represent this sound.
Romance Languages
Latin and Romanian
Latin and Romanian did/do have the letter h, which it was/is pronounced /h/, like most Germanic languages.
Spanish
Spanish does not naturally have the sound /h/, but in some dialects in Central and South America, the sound /h/ is used for the letter j. NOTE: This is only a few dialects, it is more standard to pronounce j as /x/ after back vowels, and /ç/ elsewhere!
French
In Normandy, which was occupied by the Norman (Viking) peoples, they brought the /h/ sound with them into Old Norman French. Even today, the Norman French language is spoken with a /h/ sound.
Italian
In Lombardy, originally occupied by the Germanic speaking Langobards (Long Beards), some cases have still retained the Germanic glottal fricative in pronunciation.
Hebrew and Arabic
The Hebrew and Yiddish symbol for the /h/ sound is ה. The Arabic symbol for it is ه.
Ancient Egyptian
The symbol for /h/ was a reed shelter.
Hawai'ian
Hawai'ian has the /h/ as an important part of its limited number of consonants.
Turkish
Turkish also uses the symbol h for the glottal fricative /h/.
Sources
This page is by Timothy Patrick Snyder
