||The note you refer to is a bit misleading, because even though the format of the SRTM .hgt files is band interleaved by line (BIL), they still need an associated header file before ArcMAP can recognize them. The header file is a file with the same name as the .bil file, but with a .hdr extension. It is an ASCII file (i.e., use Notepad to edit it), and it contains the information that ArcMAP needs to understand the specific contents of the .bil file.
The note correctly identifies the fields required for the 3 arc-second SRTM file N37W105.bil, and those fields are:
BYTEORDER M (for big-endian byte order in the file)
LAYOUT BIL (for band interleaved by line format)
NROWS 1201 (for 1201 rows in the raster)
NCOLS 1201 (for 1201 columns in the raster)
NBANDS 1 (for a single band in the file)
NBITS 16 (for the number of bits for each cell)
BANDROWBYTES 2402 (number of bytes in each row of the band)
TOTALROWBYTES 2402 (total bytes in each row)
BANDGAPBYTES 0 (for no gaps between the bands in the file)
NODATA -32768 (for the NoData value)
ULXMAP -104.99958333333334 (for the x coordinate (in decimal degrees) of the center of the cell in the upper left corner of the raster)
ULYMAP 38.00041666666667 (for the y coordinate (in decimal degrees) of the center of the cell in the upper left corner of the raster)
XDIM 0.000833333333333 (for the x difference (in decimal degrees) between cell centers)(at 3 arc-seconds)
YDIM 0.000833333333333 (for the y difference (in decimal degrees) between cell centers)(at 3 arc-seconds)
Each field name (i.e., BYTEORDER) and its corresponding value (i.e., M) appears on a single line in the .hdr file, and the field name and value are separated by spaces.
Once you build a header file (.hdr) to go along with your downloaded .hgt (.bil) file, ArcMAP will read it in just fine. The note is correct when it says that you can't edit the file unless you convert it to a GRID file first.
Hope this helps!